Zoosyst. Evol. 99 (1) 2023, 217-252 | DOI 10.3897/zse.99.90114 yee BERLIN Phylogenetic revision of Echinolaophonte Nicholls (Copepoda, Harpacticoida, Laophontidae T. Scott) including the establishment of two new genera and two new species Sung Joon Song!*, Sang-kyu Lee*, Mijin Kim°, Kai Horst George*, Jong Seong Khim? GeoSystem Research Corporation, 172 LS-ro, Gunpo-si, Gyeonggi-do 15807, Republic of Korea School of Earth and Environmental Sciences, Research Institute of Oceanography, Seoul National University, Seoul 08826, Republic of Korea CHA Fertility Center Seoul, Seoul 04637, Republic of Korea Senckenberg am Meer, German Centre for Marine Biodiversity Research DZMB, Siidstrand 44, 26382, Wilhelmshaven, Germany > CW NM https://zoobank. org/3A 394AE0-2903-48B6-9D30-83F'C22112B05 Corresponding authors: Jong Seong Khim (jskocean@snu.ac.kr), Kai Horst George (Kai.George@senckenberg.de) Academic editor: Kay Van Damme @ Received 8 July 2022 Accepted 27 January 2023 Published 20 March 2023 Abstract The record of a new species of Echinolaophonte Nicholls, 1941 (Copepoda, Harpacticoida, Laophontidae) from Jeju Island (Korea) formed the basis for a detailed and exhaustive phylogenetic revision of the genus. Comparison of all 15 species currently assigned to Echinolaophonte (including the new Korean species) revealed that its current composition cannot be maintained. The phylogenetic relationships within /'chinolaophonte were elucidated through the analysis of 135 morphological characters and the inclusion of four outgroups. As a result, four species were removed from Echinolaophonte and placed in two new genera: Parechinolaophonte gen. nov. for E. tropica Ummerkutty, 1970 and Pseudechinolaophonte gen. nov. for E. minuta Cottarelli & Forniz, 1991, £. mordoganensis Kuru, S6nmez & Karaytug, 2019 and £. veniliae Cottarelli, Forniz & Bascherini, 1992. Echinolaophonte longantennata Apostolov, 1990 had to be excluded from the analysis, due to the fragmentary and imprecise description. Accordingly, the phylogenetic relationships of the ten species remaining in Echinolaophonte are clarified. The new Korean species 1s described as Echinolaophonte musa sp. nov. Furthermore, the subspecies £. armiger f. briani Lang, 1965 is elevated to species rank as FL. briani Lang, 1965. A detailed phylogenetic discussion 1s provided and a key to the species of Echinolaophonte is given. Key Words crustacea, meiofauna, Pacific Ocean, systematics, taxonomy Introduction Nicholls (1941) proposed the laophontid genus Echinolaophonte Nicholls, 1941, for Laophonte horrida (Norman, 1876) as the type species, collected from the Davis Strait (western Greenland) (Norman 1876). He also transferred L. brevispinosa Sars, 1908 (Norwegian Sea), L. armiger Gurney, 1927 and L. mirabilis Gurney, 1927 (Suez Canal, Egypt) to Echinolaophonte. In that con- text, Nicholls (1941) regarded L. hystrix Brian, 1928 and L. steueri van Douwe, 1929 (both from the Mediterranean Sea) as junior synonyms of E. armiger. When describing E. armiger f. typica Lang, 1965 from the Mediterranean Sea and E. armiger f. briani Lang, 1965 from the Californian coast (U.S.A.), Lang (1965) was the first to discuss the possible phylogenetic relationships within Echinolaophonte. He meant to recognise two evolutionary lineages. The first is characterised by 3:3:2 outer spines on the P2—P4 exp-3, respectively and by a sexually dimorphic male P3 endopod. In the second lineage, the P2—P4 exp-3 bear 2:3:2 outer Spines, respectively and the sexual dimorphism in the male P3 endopod is lost. Lang’s (1965) hypothesis was subsequently questioned by Mielke (1981) who noted Copyright Song, S.J. et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 218 that FE. tetracheir Mielke, 1981 combines the P2—P4 setation (3:3:2) observed for the first lineage and the loss of sexual dimorphism observed for the second lineage. Furthermore, Mielke (1981) noted that FE. gladiator Vervoort, 1964 cannot be assigned to either of the two lineages, because its P2—P4 exp-3 present 2:2:2 outer spines. Therefore, Mielke (1981) rejected the setation of the swimming legs as phylogenetically relevant for the establishment of the two lineages. This was subsequently adopted by Cottarelli and Forniz (1991) and Cottarelli et al. (1992), because both E. minuta Cottarelli & Forniz, 1991 and E. veniliae Cottarelli, Forniz & Bascherin1, 1992 combine the sexual dimorphism observed for the first lineage with the setation pattern 2:3:2 of P2—P4 exp-3 observed for the second lineage. Like Mielke (1981), Cottarelli and Forniz (1991) and Cottarelli et al. (1992) considered the loss of sexual dimorphism in the male P3 endopod as a valuable phylogenetic character. Cottarelli et al. (1992) proposed two groups, viz. the “horrida’ group with and the “armiger” group without sexual dimorphism in the male P3 endopod. According to Cottarelli et al. (1992), the “horrida” group encloses E. horrida, E. brevispinosa, E. oshoroensis It6, 1969, E. tropica Ummerkutty, 1970, E. minuta and E. veniliae and the “armiger” group includes E. armiger f. typica, E. armiger f. briani and E. tetracheir. The “horrida” group was recently updated by Kuru et al. (2019) in the framework of their description of E. mordoganensis Kuru, Sonmez & Karaytug, 2019. They included E. mordoganensis into the “horrida” group, but excluded E. tropica, since “E. tropica Ummerkutty, 1970 cannot be included in any of the lineages” (Kuru et al. 2019: 183), due to confusing information with respect to the male’s P3 endopod provided by Ummerkutty (1970), Wells and Rao (1987) and Wells (2007). Furthermore, Kuru et al. (2019) pointed to the pending assignment of E. mirabilis, E. longantennata Apostolov, 1990 and E. gladiator to any of the groups, since no males of these species have been described so far. Lee et al. (2006) fully re-described FE. armiger (Gurney, 1927), based on specimens collected from the Texan coast (U.S.A.) and compared them with the type specimens deposited in the Natural History Museum (London, U.K.). To clarify the taxonomy of E. armiger, Lee et al. (2006) carefully re-examined all records of E. armiger since the original publication by Gurney (1927) (namely Willey 1930; Nicholls 1945; de Paiva Carvalho 1952; Krishnaswamy 1957; Pesta 1959 (as Onychocamptus armiger);, Vervoort 1964 (also as O. armiger), Lang 1965). They noted that Nicholls’ (1945) and Vervoort’s (1964) records of E. armiger from western Australia and the Caroline Islands, respectively, show a remarkable resemblance, but in fact do belong to a distinct, new species. However, Lee et al. (2006) desisted from describing that species, due to the availability of only few damaged specimens. They concluded that the “true” EF. armiger reported from the Suez Canal by Gurney (1927) had subsequently been recorded only two zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte times, 1.e. from Bermuda (Willey 1930) and from Brazil (de Paiva Carvalho 1952). Instead, the specimens of (the supposed) E. armiger reported from Madras (India) (Krishnaswamy 1957), from the Cape of Sorrento (Italy) (Pesta 1959) and from the Californian Pacific coast (U.S.A.) (Lang 1965), presumably are more closely related to E. hystrix, which, motivated by Lang’s (1965) description of E. armiger f. typica, was re-instated by Lee et al. (2006) as a valid species. Wells (2007) recognised 11 species in Echinolaophonte and regarded E. armiger sensu Nicholls (1945), E. armiger f. briani, Onychocamptus armiger sensu Pesta (1959) and O. armiger sensu Vervoort (1964) as species inquirendae. Fuentes-Reinés and Suarez-Morales (2017) investigat- ed specimens of E. armiger obtained from Rodadero Bay (Colombia). A detailed comparison showed that, besides findings of E. armiger sensu Gurney (1927), the Colom- bian specimens represent a new species, but were “almost identical” with Nicholls’ (1945) and Vervoort’s (1964) material (Fuentes-Reinés and Suarez-Morales 2017: 28), thus confirming the assumption of Lee et al. (2006) about the Pacific specimens constituting a new species. They described the new species as F. villabonae Fuentes-Re- inés and Suarez-Morales, 2017 and provided a key to the species of Echinolaophonie. While examining collections of laophontid spe- cies deposited at the School of Biological Sciences, Seoul National University, we found a new species of Echinolaophonte obtained from the subtidal soft bottoms of Jeju Island, Korea. Here, we fully describe and illustrate it as E. musa sp. nov. Our attempt to clear the systematic relationship of the new species within Echinolaophonte required a fundamental, exhaustive phylogenetic analy- sis of the genus that is presented herein. Moreover, we provide an amended identification key to the species of the genus. Methods The specimens were collected by SCUBA diving from subtidal sandy bottoms at a depth range of 20-30 m at Munseom islet, Jeyu Island. The material was sieved with a 38 mm mesh and fixed in 95% ethanol. Benthic harpacticoid copepods were sort- ed in the laboratory using a Leica M165C (Germany) ste- reomicroscope. Specimens were then embedded in glyc- erol and dissected. The slide preparations were sealed with transparent nail varnish. Species identification and drawings were prepared using a drawing tube on an Olympus BX53 (Tokyo, Japan) differential interference contrast microscope, equipped with Nomarski optics. Confocal Laser Scanning Microscopy (CLSM) was used at the DZMB (Senckenberg am Meer Wilhelmshaven, Germany) to examine the individuals, applying the methods shown, for example, in George et al. (2020). The phylogenetic analysis strictly follows the concept of a “consequent phylogenetics” as developed Zoosyst. Evol. 99 (1) 2023, 217-252 by Hennig (1982) and substantiated by Ax (1984, 1988, 1995). It consists of a detailed and comparative character discussion that enables the formulation of an intersubjective hypothesis (Ax 1984). Computer programmes were used neither for the phylogenetic analysis nor for the generation of the presented cladogram (Fig. 10): it was not the aim of the contribution at hand to provide a methodological comparison of (hand-made and computer-based) phylogenetic analyses, but to present a first hypothesis of the systematics of and within the family under investigation; future phylogenetic analyses can use the matrix presented herein as a detailed morphological dataset. Fig. 10 represents the condensed result from the formerly undertaken detailed and complex phylogenetic analysis. Concerning the number of segments and setae/spines, the generally accepted principle of oligomerisation (Huys and Boxshall 1991; Seifried 2003), which postulates that a reduction of segments/ elements constitutes the relatively more derived state, was adopted here. The underlying morphological comparison of the used characters was made, based on the respective original Species (re-)descriptions. The terminology used follows Huys and Boxshall (1991) and Huys et al. (1996). The term “telson” is ad- opted from Schminke (1976). Phylogenetic terminology is adopted and translated from Ax (1984). Abbreviations used in the text AJ, antennule; A2, antenna; ae, aesthetasc; ephth, ceph- alothorax; CR, caudal ramus/rami; GDS, genital dou- ble somite; md, mandible; mx, maxilla; mxl, maxillula; mxp, maxilliped; P1—P6, first to sixth thoracopod; exp (enp)-1 (2, 3) to denote the proximal (middle, distal) seg- ment of a ramus. Scale bars are in micrometres (um). The type speci- mens are deposited in the collection of The Natural In- stitute of Biological Resources (NIBR), Incheon, Korea and The National Marine Biodiversity Institute of Korea (MABIK), Seochun, Korea. Results Subclass Copepoda Milne Edwards, 1840 Order Harpacticoida Sars, 1903 Family Laophontidae T. Scott, 1905 Genus Echinolaophonte Nicholls, 1941 Generic diagnosis (modified from Nicholls 1941). Laophontidae T. Scott, 1905. Body elongate, cylindrical, podoplean boundary between pro- and urosome inconspicuous. Sexual dimorphism in Al, P3 (in the brevispinosa—oshoroensis clade only; not yet confirmed for E. gladiator), P4 (part.), P5, P6 and 219 urosome segmentation (female with GDS due to fusion of last (P6-bearing, genital) thoracic somite with first abdominal somite). Cphth about 1/3 of total body length, with some sensilla laterally and dorsally; with strong, acute dorsal spur on posterior margin. Rostrum fused to cphth, laterally constricted, of different shape (dome, truncate, notch etc). Body somites, except preanal and telson, dorsally with cuticular processes of variable lengths. Preanal somite with highly variable pseudoperculum consisting of several, often digitate or Squarrose processes (sometimes partly fused together). CR longer than broad, varying in length between species, with 7 setae. Female Al slender, 6-segmented; male Al sexually dimorphic, 8-segmented, subchirocer. A2 with l-segmented exopod bearing 4 setae; allobasis with 1 or lacking abexopodal seta; endopod 1-segmented, subdistally with 2 spines and 1| slender additional seta, apically with 6 setae (2—3 geniculate)/spines. Mxp with elongated syncoxa and basis, prehensile, apical claw as long as basis. P1 prehensile, with extremely elongated coxa and basis, the latter reaching the length of enp- 1. Exopod small, 2-segmented; endopod 2-segmented, enp-1 extremely elongated, enp-2 very small, with 1 strong claw and | tiny seta apically; P2—P4 with 3-segmented exopods, female with 2-segmented endopods; if sexually dimorphic, male P3 endopod 3-segmented, with strong apophysis on outer apical edge; those males lacking sexual dimorphism on P3 with 2-segmented endopod, resembling that of the female. Exopods of male P3 and P4 with or without sexual dimorphism. P5 of female with baseoendopod bearing 4 setae and with small distinct exopod carrying 3 setae. Male P5 smaller than in female, baseoendopod completely reduced; exopod distinct and small, with Ssetde: Type species. Echinolaophonte horrida (Norman, 1876) (= Cleta horrida Norman, 1876; Laophonte horrida (Brady, 1880); Onychocamptus horridus (Lang, 1948)). Additional species. E. armiger (Gurney, 1927) (= Laophonte armiger Gurney, 1927; Onychocamptus armiger (Lang, 1948); Echinolaophonte armiger f. typica (Lang, 1965)); E. brevispinosa (Sars, 1908) (= Laophonte brevispinosa Sars, 1908; Onychocamptus brevispinosus (Lang, 1948)); E. briani Lang, 1965 (= E. armiger f. briani Lang, 1965); E. gladiator (Vervoort, 1962) (= Onychocamptus gladiator Vervoort, 1964); E. hystrix (Brian, 1928) (= Laophonte hystrix Brian, 1928; L. steueri van Douwe, 1929; E. armiger (Norman, 1941); O. armiger (Lang, 1948, Vervoort, 1964); E. armiger f. typica (Lang, 1965; Lee et al. 2006)); E. longantennata Apostolov, 1990; E. mirabilis (Gurney, 1927) (=Laophonte mirabilis Gurney, 1927; Onychocamptus mirabilis (Lang, 1948)); E. musa sp. nov. (present contribution); E. oshoroensis It6, 1969; E. tetracheir Mielke, 1981; E. villabonae Fuentes-Reinés and Suarez-Morales, 2017. zse.pensoft.net 220 Echinolaophonte musa sp. nov. https://zoobank.org/1550C93D-4255-4830-9B5C-6952A27BA0BB Figs 2-8 Korean name: Mu-Sa-Chim-Ga-Hok-No-Beol-Re Locus typicus. Munseom Islet, Jeyu Island, Korea, 33°13'42"N, 126°34'02"E, subtidal sandy bottom (20-30 m in depth) (Fig. 1). Type material. Adult female holotype (NI- BRIV0000888158) dissected on 12 slides (Rostrum and Al; A2; mandible; maxillule; maxilla; maxilliped; P1; P2; P3; P4; P5; urosome), Munseom Islet, Jeyu Island, Korea, coll. H.S. Rho, 01 Oct. 2002. Male allotype (NI- BRIV0000888157) dissected on 12 slides (Rostrum; Al; A2; maxilla; maxilliped; P1; P2; P3; P4; P5; cphth; urosome). Paratypes: two females and five males, undis- sected, ethanol-preserved in vial (NIBRIV0000888156) and two females and four males, as above (MABIK- CRO00248285-CR00248290). Additional studied material. 1 female and 1 male, ethanol-preserved, Munseom Islet, Jeyu Island, Korea, coll. H.S. Rho, 06 Oct. 2002; 1 male, undissected, etha- nol-preserved, Sagyeri, Jeju Island, 4 Sep 2008; 2 females and 1 male, undissected, ethanol-preserved, Sungsanpo, Jeju Island, 12 May, 2013, coll. SH. Kim, deposited at the National Marine Biodiversity Institute of Korea (reg. no. MADBK 721114-001). Description of the female. Habitus (Figs 2, 3A) slen- der, demarcation between pro- and urosome not clearly discernible, body somites virtually cylindrical. Total body length 660.6 um (660.6—736.4 um, mean = 713.1, n= 6), measured from the anterior margin of the rostrum to the posterior margin of the caudal rami. Urosome (Fig. 6A) gradually tapering posteriorly. All body somites with paired horn-like spiniform processes bearing long sensil- la, except for last two abdominal somites. Paired dorsal processes from first pedigerous somite to first abdominal somite (5 segments, GDS with two pairs of processes) with bifid tip. Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Cephalothorax (Figs 2, 3A) with two small and one long spiniform processes bearing numerous fine, hair-like elements at the mid-line of dorsal surface and a pair of strong and curved lateral processes; with a few scattered spinules and long sensilla. Rostrum very long and stout, with bifurcated tip as shown. Urosome (Figs 3A, 6A) 5-segmented, comprising P5-bearing somite, genital-double somite, 2 free abdom- inal somites and telson. Genital double-somite (Fig. 6A) slightly wider than long, with long spinules along outer margins. P6 (Fig. 6B) represented by 2 long bare setae on a bilobed single plate covering gonopores. Third uroso- mite widened distally, with long spinules along the outer and distal margins and with 4 long sensilla on the distal corners. Fourth urosomite with fine spinules along the distal margin. Pseudoperculum represented by 3 squar- rose lobes (Fig. 3B). Caudal ramus (Fig. 3C) long and narrow, about 5.3 times as long as greatest width, with a few spinules around setae I and III; with seven bare setae; seta I shortest, setae [V—VI situated distally, seta VII tri-articulate at base, inserted subapically on dor- sal surface. Antennule (Figs 4A, B) 6-segmented, all setae bare; segment 1 longest, with long spinular row on inner and outer margins, with 1 seta distally; segment 2 with short inner and long outer spinular row, with 3 short and 4 long bare setae; segment 3 slightly shorter than seg- ment 2, with 5 long setae; segment 4 small, distally with aesthetasc and 2 setae, arising from pedestal; segment 5 shortest, with 1 seta; segment 6 (Fig. 4B) with 8 single setae and an acrothek formed by 2 setae and 1 aesthetasc. Setal formula: 1-[1], 2-[7], 3-[5], 4-[2 + ae], 5-[1], 6-[8 + acrothek (2 + ae)]. Antenna (Fig. 4C) comprising coxa, allobasis, free en- dopodal segment and 1-segmented exopod. Coxa small, without ornamentation. Allobasis as long as endopod, with spinular row along inner margin and with 1 small bare abexopodal seta (arrowed in Fig. 4C). Exopod long and 1-segmented, bearing spinules on outer margin, with 125°E 130°E -40°N Korea -35°N 126.5°E Figure 1. Map of the locus typicus (Munseom Islet) of Echinolaophonte musa sp. nov. and additional sampling localities of the species. zse.pensoft.net Zoosyst. Evol. 99 (1) 2023, 217-252 1 inner and 3 distal setae. Endopod with spinular row along inner margin. Subdistal armature consisting of 1 seta (I in Fig. 4C) and 2 spines (II and III in Fig. 4C); distal armature consisting of 2 setae (1 and 2 in Fig. 4C), 2 spines (3 and 6 in Fig. 4C) and 2 geniculate setae (4 and 5 in Fig. 4C). Mandible (Fig. 4D). Gnathobase with 4 teeth (1 bi-, 1 tri-cuspidate and 2 with distal spinules) and 1 long unip- innate seta in dorsal corner as depicted; surface without ornamentation. Palp 1-segmented, carrying 1 lateral and 2 distal setae. Maxillule (Fig. 4E). Praecoxa without ornamentation. Arthrite well-developed, with 7 distal spines/setae and 2 anterior surface setae. Coxa with few setules on inner margin, with 1 unipinnate and 1 bare seta distally. Basis with several spinules along inner and outer margin, with 1 unipinnate and 2 bare setae distally. Exopod 1-segment- ed, elongated, with 2 bare setae distally. Endopod repre- sented by 2 plumose setae. Maxilla (Fig. 4F). Syncoxa with a long spinular row on the outer surface and lots of tiny spinules on the inner proximal surface and with 2 endites, both fused to the syncoxa; proximal endite with 2 bare and | multipinnate setae, the latter fused to endite; distal endite with 1 bare, 1 bipinnate and | unipinnate seta, the latter fused to endite. Allobasis drawn out into strong claw with 1 accessory seta; Endopod represented by 2 bare setae. Maxilliped (Fig. 5A). Well-developed, prehensile, with elongated syncoxa and basis. Syncoxa with sever- al spinules proximally and subdistally and with 1 short bare and | plumose distal seta. Basis elongated, with few spinules on middle outer margin. Endopod represented by an apically curved claw, slightly longer than basis; acces- sory armature consisting of 1 bare proximal seta. Pl (Fig. 5B). Intercoxal sclerite narrow, bow-like. Praecoxa small, elongated, triangular, with few small spinules on distal corner. Coxa elongated, with long outer and short inner spinules. Basis about 2 times as long as coxa, with a small outer protuberance on the proximal quarter and setule rows on posterior surface, inner and outer margins; with | outer seta in proximal third and 1 tiny inner seta subdistally. Exopod 2-segmented, much shorter than enp-1; exp-1 tiny, almost square in shape, with | outer seta; exp-2 about 3 times longer than exp-1, with 2 long outer setules, 3 outer and 2 distal bare setae; inner distal seta geniculate. Endopod 2-segmented, pre- hensile; enp-1 very long, without ornamentation; enp-2 with a tiny seta and a strong claw, the latter about 2 times longer than enp-2. P2 (Fig. 6C). Intercoxal sclerite narrow, unornamented. Praecoxa triangular, unornamented. Coxa almost square, with few spinules on outer surface. Basis smaller than coxa, with few spinules and pore on outer distal surface and with 1 biplumose outer seta. Exopod 3-segmented; exp-1 with spinules on outer margin and 1 short spinu- lar row distally and with 1 bipinnate outer spine; exp-2 shortest, with spinules on outer and distal margin; with 1 bipinnate outer spine and 1| biplumose inner seta; exp- 3 with spinules on outer margin, with 3 bipinnate outer nA Figure 2. Confocal laser scanning of Echinolaophonte musa sp. nov. female. Habitus, dorsal view. zse.pensoft.net 222 Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Figure 3. E'chinolaophonte musa sp. nov. female. A. Habitus, lateral; B. Pseudoperculum; C. Caudal ramus, dorsal view. zse.pensoft.net Zoosyst. Evol. 99 (1) 2023, 217-252 spines, 2 distal and 1 inner seta, all biplumose. Endopod 2-segmented, reaching proximal third of exp-3; enp-1 with inner and distal spinules; enp-2 slightly longer than enp-1, with spinules along both margins and with 2 distal and | inner seta. P3 (Fig. 6D). Intercoxal sclerite narrow, unornament- ed. Praecoxa triangular, with spinular row on distal mar- gin. Coxa slightly wider than long, with few spinules on outer surface. Basis nearly as long as coxa, with spinules on outer distal surface and with 1 bare composite outer seta; articulation in the distal third. Exopod 3-segmented; exp-1 with spinules on outer margin and | bipinnate outer spine; exp-2 shortest, with outer and distal short spinules, with | bipinnate outer spine and | biplumose inner seta; exp-3 with spinules on outer margin and with 3 bipin- nate outer spines, 2 distal and 2 inner biplumose setae. Endopod 2-segmented, almost reaching margin of exp-2; enp-1 much shorter than enp-2, with spinules along both margins; enp-2 with spinules on both margins, addition- ally with 2 distal and 2 inner setae. P4 (Fig. 6E). Intercoxal sclerite narrow, unornamented. Praecoxa small and triangular, with few tiny spinules along distal margin. Coxa as long as wide, with outer spinule. Ba- sis with outer spinules and 1 bare composite outer seta. Ex- opod 3-segmented; exp-1 with spinules on outer and distal margins and with 1 bipinnate outer spine; exp-2 shortest, with outer and distal spinules, with | bipinnate outer spine and | biplumose inner seta; exp-3 with spinules on outer and distal margins, with 1 bipinnate spine and | biplumose seta on outer margin, 2 inner and 2 distal biplumose setae. Endopod 2-segmented, shorter than exp-1; enp-1 short and with few tiny outer spinules; enp-2 with a spinule and 1 tube pore on outer margin, with 2 distal and | inner bi- plumose seta. The armature formula is given in Table 1. Table 1. Setal formula of swimming legs of Echinolaophonte musa sp. nov. Thoracopod Exopod Endopod P2 01123 0120 P3 01 223 0 220 P4 01 222 0120 P5 (Fig. 5C) with completely separated baseoendopod and exopod. Baseoendopod reaching middle of exopod, with outer seta arising from elongated setophore bearing 1 tube pore (arrowed) and some spinules at distal half; en- dopodal lobe reaching half the length of exopod, apically with 1 tube pore (arrowed) and 4 setae. Exopod longer than broad, with spinules on inner and outer margins and distal surface, with 3 plumose setae distally. Description of male. Total body length 648.5 um (642.4—721.2 um, mean = 681.8 um, n = 10), measured from anterior margin of rostrum to posterior margin of caudal rami (Fig. 7A). Urosome (Fig. 8E) gradually taper- ing posteriorly. Cephalothorax as in female, with numer- ous fine, hair-like elements and long sensilla on surface as shown in Fig. 7C; paired cuticular dorsal processes of 223 first pedigerous somite trifid, those of second pedigerous somite to fourth urosomite with bifid tip. Rostrum very similar to female (Fig. 7A). Urosome (Figs 7C, 8E) 6-segmented, comprising P5-bearing somite, genital somite, third to fifth uroso- mite and telson. Genital somite and telson without, third to fifth urosomites with long spinules ventrally on distal margin; third and fourth somites with remarkably long sensilla on each distal corner. Pseudoperculum (Fig. 8F) represented by 2 pairs of lobes, inner pair with 3 respec- tively 4 spikes, outer lobes squarrose; the margin in be- tween the lobes bearing fine setules. Antennule (Fig. 8B) 8-segmented; subchirocer, with geniculation between segments 5 and 6; segment | lon- gest, with numerous spinules on anterior and posterior surfaces and with 1 small seta on anterior distal corner; segment 2 with long spinules on surface and both margins and with 8 setae, two of which arising from strong ped- estal; segment 3 with 3 setae; segment 4 smallest, with 4 setae; segment 5 swollen, with 9 bare setae, 1 bipinnate seta and | long seta and aesthetasc arising from long ped- estal; segment 6 unarmed; segment 7 with 1 seta; segment 8 with 8 setae and acrothek (2 setae and 1 aesthetasc). Setal formula: 1-[1], 2-[8], 3-[7], 4-[11 + ae], 5-[0], 6-[1], 7-[8 + acrothek (2 + ae)]. Antenna, mouthparts and P1, P2 and P4 as in female. P3 (Fig. 8D). Both rami very similar to female, except for 2 strong outer pinnate spines (arrowed) on exp-1 and exp-2. PS (Fig. 7B) with separated baseoendopod and exopod. Baseoendopod with few spinules on anterior surface and distally, 1 tube pore subdistally and 1 outer bare compos- ite seta. Exopod elongate, with 3 biplumose setae distally. P6 (Fig. 7C) very small, bearing a few setules, 1 outer bare composite and 1 plumose inner seta. Etymology. The epitheton originates from the Korean word ‘mu-sa [4f]’, which means “warrior”. Phylogenetic analysis. Currently, the taxon Echinola- ophonte encloses 16 species: E. armiger, E. brevispinosa, E. briani, E. gladiator, E. horrida, E. hystrix, E. longanten- nata, E. minuta, E. mirabilis, E. mordoganensis, E. musa sp. nov., £. oshoroensis, E. tetracheir, E. tropica, E. venil- iae and E. villabonae. These are in the following referred to as “Echinolaophonte-CS” (“current status”) to distinguish them from both Nicholls’ (1941) and the new combination proposed herein (see Discussion). Based on 135 morpholog- ical characters (Table 2), an exhaustive phylogenetic analysis was undertaken. It included the comparison of 15 Echinola- ophonte-CS species; E. longantennata was excluded from the phylogenetic analysis (see below). Furthermore, with Coullia Hamond, 1973 (mostly exemplified by C. tongariki (Gomez & Boyko, 2006)), Hemilaophonte janinae (Jakubi- siak, 1933) and Xanthilaophonte Fiers, 1991, three poten- tial close relatives were selected as outgroups. This is con- sidered here as necessary, because they share features that were seen as characteristic for Echinolaophonte by Nicholls (1941). Moreover, Heterolaophonte minuta (Boeck, 1872) was added as a fourth outgroup to include a comparatively distant representative of Laophontidae. zse.pensoft.net 224 Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Figure 4. Echinolaophonte musa sp. nov. female. A. Antennule; B. Distal segment of antennule; C. Antenna; arrow pointing to abex- opodal seta; Roman numerals labelling subapical, Arabian numerals labelling apical elements; D. Mandible; E. Maxillule; F. Maxilla. zse.pensoft.net Zoosyst. Evol. 99 (1) 2023, 217-252 225 Figure 5. Echinolaophonte musa sp. nov. female. A. Maxilliped; B. P1; C. P5; arrows point to tube pores. zse.pensoft.net 226 Song, S.J. et al.: Phylogenetic revision of Echinolaophonte eee oe ee Figure 6. Echinolaophonte musa sp. nov. female. A. P2; B. P3; C. P4. zse.pensoft.net Zoosyst. Evol. 99 (1) 2023, 217-252 227 30 30 Figure 7. Echinolaophonte musa sp. nov. A. Female urosome, ventral view; B. female P6; C. Male habitus, lateral view; D. Male P5; E. Male P6. zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte 228 Figure 8. Echinolaophonte musa sp. nov. male. A. Rostrum; B. Antennule; C. Dorsal processes on first pedigerous somite to fourth urosomite; D. P3; E. Urosome, ventral view; F. Pseudoperculum. zse.pensoft.net Zoosyst. Evol. 99 (1) 2023, 217-252 Eightteen out of 135 characters (= 13.3%) emerged as convergent deviations. They mostly distribute heter- ogeneously over the species and are set in underlined bold italics in Table 2. Vertical arrows in characters 31 and 32 (Table 2) point towards a further deviation in E. oshoroensis (see Discussion). The results of the phylogenetic analysis are discussed in detail below. The resulting phylogenetic relationships are presented in Fig. 10. The cladogram shows the 135 apomorphies spread over the respective nodes (Figs 10, A-EE). For a better orientation, the different nodes, as well as their assigned clades and characters, are sum- marised in Table 3, with the hypothesised convergences set in underlined bold italics. The results suggest that Echinolaophonte-CS consists of several subordinated clades that complicate an unam- biguous characterisation of the genus (Fig. 10). Echinola- ophonte longantennata had to be excluded from the phylo- genetic analysis due to the imprecise and only fragmental description provided by Apostolov (1990), combined with the lack of material for re-examination and comparison. Two synapomorphies were detected for the remaining 15 Species, namely a narrowed rostrum (Table 2, character 13) and the syncoxa of the mxp being almost as long as the basis (Table 2, character 14). Nonetheless, a further careful comparison resulted in the division of Echinolaophonte— CS: E. tropica was placed into Parechinolaophonte gen. nov. as Pa. tropica (Ummerkutty, 1970), gen. et comb. nov., based on six autapomorphies (Table 2, characters 15—20; cf. Fig. 10, node F) and E. minuta, E. mordoganensis and E. veniliae were transferred into Pseudechinolaophonte gen. nov. as Ps. minuta (Cottarelli & Forniz, 1991), gen. et comb. nov., Ps. mordoganensis (Kuru, S6nmez & Karay- tug, 2019), gen. et comb. nov. and Ps. veniliae (Cottarelli, Forniz & Bascherini, 1992), gen. et comb. nov., based on 14 synapomorphies (Table 2, characters 23-36; cf. Fig. 10, node H). The 11 species remaining in Echinolaophonte can be characterised by means of one synapomorphy (Table 2, character 54, cphth with single spur dorsally on posterior margin; cf. Fig. 10, node H). In the following, the generic diagnoses of the two new genera are given. Parechinolaophonte gen. nov. https://zoobank. org/EE6E9 1 A6-34BC-4765-B667-892B66C88 117 Diagnosis. Laophontidae T. Scott, 1905. Body elongate, cylindrical, podoplean boundary between pro- and uro- some inconspicuous. Whole body minutely punctate. Sexual dimorphism in Al, P5 and P6; female with GDS. Cphth reaching about 1/3 of total body length; lateral mar- gins of cphth extended outwardly, triangular; distal outer edges of cphth with paired backwardly directed protru- sions, dorsally with longitudinal cuticular ridge crossed by 2 furrows. Rostrum fused to cphth, laterally constrict- ed, almost square. Body somites without pronounced dor- sal cuticular processes; abdominal somites, except telson, with weakly developed cuticular spinulose structures on 229 posterior margins. Pseudoperculum weakly developed, consisting of 4 small protrusions bearing several fine spinules apically. CR about twice as long as broad, with 7 setae (cf. Wells and Rao (1987), fig. 1431). Female Al slender, 6-segmented; male Al subchirocer, number of segments unknown. A2 with 1-segmented exopod bearing 4 setae, allobasis with 1 abexopodal seta; endopod 1|-seg- mented, with 2 lateral spines and 5 apical setae/spines (cf. Wells and Rao (1987), fig. 143}). Mxp prehensile, syncoxa and basis of approximately the same length; syncoxa with 1 pinnate seta on apical margin, basis with spinulose field on anterior margin; claw massive, accompanied by min- ute seta. Pl prehensile, with extremely elongated coxa and basis, the former massive and larger than the latter, nearly reaching the length of enp-1. Exopod 2-segmented, more than half the length of enp-1; exp-1 half as long as exp-2, with | outer spine, exp-2 with 3 outer and 2 apical spines/ setae. Endopod 2-segmented, enp-1 extremely elongated, massive, enp-2 small, apically with | strong curved claw and 1 tiny seta. P2—P4 with 3-segmented exopods and 2-segmented endopods. Female P5 with baseoendopod bearing 4 setae; exopod fused with baseoendopod, with 3 setae. Male P5 with completely reduced baseoendopod, exopod small and distinct, with 3 setae. Female “genital field simple, without trace of P6” (Wells and Rao 1987: 177); male P6 small, with 1 seta and 1 strong spine. Etymology. The generic name is composed of the Greek prefix pard-, meaning similar and the generic name Echinolaophonte. Gender: feminine. Type and only species. Parechinolaophonte tropica (Ummerkutty, 1970), gen. et comb. nov., by orig- inal designation. Pseudechinolaophonte gen.nov. https://zoobank.org/03B3 1 6FE-329E-476B-B 1 BB-F51289DAA8A0 Diagnosis. Laophontidae T. Scott, 1905. Body elongate, cylindrical, podoplean boundary between pro- and uro- some inconspicuous. Sexual dimorphism in the Al, P3, PS and P6; female with GDS. Cphth almost squarish, reaching about 1/3 of total body length; dorsally with spinulose, broad cuticular projection bearing 2—4 apical spikes on posterior margin (cf. Fig. 9A). Rostrum small, laterally constricted, square, fused to cphth. Thoracic body somites with paired strong spikes centrally on the posterior margin (cf. Fig. 9A); abdominal somites, except telson, dorsally with sclerotised clasp-like area bearing 2 spikes on posterior margins (cf. Fig. 9A). First abdomi- nal somite (posterior half of female GDS) and second ab- dominal somite laterally with well-developed, wing-like epimeres (cf. Fig. 9A). Pre-anal somite with well-devel- oped pseudoperculum, with 2 strong tridentate spikes (cf. Fig. 9A), but with some variability. CR at the most twice as long as broad, with 7 setae. Female Al slender, 6-seg- mented; male Al 7—8-segmented, subchirocer. A2 with l-segmented exopod bearing 4 setae, allobasis with or without abexopodal seta; endopod 1-segmented, with zse.pensoft.net 230 22/72 Song, S.J. et al.: Phylogenetic revision of Echinolaophonte a Se AE 21/54/82 21/54/57 ae ean 22/68 mee 22/70 7 22/71 us T_T 22/73 an ee la a 22174 Pseudoperculum Figure 9. Schematic depiction of A. Pseudechinolaophonte minuta gen. et comb. nov.; B. Echinolaophonte armiger and C. Echinolaophonte horrida, illustrating and exemplifying the general shape of the cuticular structures located dorsally on the cephalothorax and free body somites of the closely-related taxa treated in the present contribution. The assigned numbers reflect the corresponding morphological characters as listed in Table 2. Explanations are given in the text. 2 lateral spines and | seta; 1 spine modified with a round- ed tip that differs between the species; apically with 5-6 setae/spines, 2-3 of which geniculate. Mxp prehensile, with elongated syncoxa and basis; syncoxa with 1—2 se- tae on its apical edge. Endopod produced into long claw that surpasses the length of the basis. P1 prehensile, with elongated coxa and basis, but none reaching the length of enp-1. Exopod 2-segmented, not reaching half the length of the enp-1. Exp-1 about twice as long as exp-2, with 1 outer spine; exp-2 with 3 outer spines and 2 apical setae. Endopod 2-segmented, enp-1 long, without any ornamen- tation; enp-2 small, apically with strong serrated claw and 1 tiny seta. P2—P4 with 3-segmented exopods, P2 and P4, as Well as female P3 endopods 2-segmented; outer basal seta of P2 biplumose, with extremely long pinnae. Male P3 and P4 sexually dimorphic; male P3 exopod more compact than in female, endopod 3-segmented, second segment with pronounced apophysis. Male P4 exopod also stronger than in female, somewhat bent inwards. P4 endopods particularly small in both sexes, not reaching the distal margin of exp-1. Female P5 with baseoendopod bearing 2 setae; exopod distinct, with 3 setae. Male PS with completely reduced baseoendopod, exopod with 3 setae. Female P6 very small, knob-like, with 2 tiny setae. Male P6 small, consisting of simple lobe carrying | small bare and | long biplumose seta. zse.pensoft.net Etymology. The generic name is composed of the Greek prefix pseudo-, meaning false or fake and the ge- neric name Echinolaophonte. Gender: feminine. Type species. Pseudechinolaophonte minuta (Cottarelly & Forniz, 1991), gen. et comb. nov., by original designation. Additional species. Ps. mordoganensis (Kuru, Sonmez & Karaytug, 2019) gen. et comb. nov., Ps. ve- niliae (Cottarelly, Forniz & Bascherini, 1992), gen. et comb. nov. Restructuring Echinolaophonte Nicholls, 1941 After the exclusion of Parechinolaophonte tropica gen. et comb. nov., Pseudechinolaophonte minuta gen. et comb. nov., Ps. mordoganensis gen. et comb. nov. and Ps. veniliae gen. et comb. nov. from Echinolaophon- te-CS, the genus Echinolaophonte retains 11 species (Fig. 10, node M). They can be characterised by the synapomorphic dorsal spur on the posterior margin of the cphth (Table 2, character 54). This dorsal cuticular spur on the posterior margin of the cphth is quite rare in Harpacticoida, had been recognised as a characteristic feature for Echinolaophonte by Nicholls (1941) and is hypothesised here as a strong synapomorphic character for all 11 species. Zoosyst. Evol. 99 (1) 2023, 217-252 231 Table 2. Matrix listing the 135 morphological characters used in the here presented phylogenetic analysis. 1 = supposed apomor- phies; 0 = supposed plesiomorphies; 7 = supposed convergent apomorphies. Vertical arrows in characters 31 and 32 point towards a further deviation in £. oshoroensis. For character state justification, see character discussion. No. Character/species (1 = apomorphy; 0 = plesiomorphy; Echinolaophonte-CS 1 = supposed convergence; ? = no data available) 2 77) ow 8-48 S o 2 a. g € g¢ gfe SeESe eR RES ) = £,fESBPESBESSRZBERS AS 5 E, Eeeugee £ chads 6 Si] ie Se Reece g, ea. Ss eee ee es = Sass .e 6 Bese = ®se 2 tg ecko tes FS QERo EQ S SEESESSRBEEB Eso S82 ESS525 8 5 asSessss2ePeasseeazes ve e°Ststesssazeasseeses & S £ S38eeetefeegees egegsgsuvusgr sag ag =u aa 5s Mm WW 2 1 P1 of characteristic laophontid shape (cf. Huys 1990) de 1 Se Dee ee aL ek Le lee dite De een eds Led 2 P2 female enp(-2) with at most 1 inner seta Ope Loar? PL me pe Le Les Le Les Lon eae Le AL 3 P3 female enp(-2) with at most 2 inner setae gl I Tt Oe aca Eg: es ed ESR a Cems ne a ns Dis Hs Ee (me De 4 P1 exopod at most 2-segmented OO. Lee Dee A ee LL eee SL ae Le ok 5 P1 coxa slender, elongate Oe Lee ee A ee Le eee SL ae Le ok 6 P1 basis slender, elongate O. LPT Lae 1 ee LL Le eed SL ae ek 7 P3 female enp(-2) without outer spine G20 tl Lee SIs Al ea ee de pl dk Sie ela ee 8 Al female 6-segmented Cp A gts ie eds a Le de Fd eo ee 9 P5 female benp with at most 4 setae OO gL Las Be el 0 a ele Le ee 10 P4 female enp(-2) without outer spine OesOeOy Gla We Ble LBL WT cl Le el Leelee Le 11 P5 female exopod with at most 3 setae 0 0011t%1d21d212éi212i41éid1ii341i434a S«zAasésd.sdidiidiii 12 Preanal somite dorsally with pseudoperculum formed by O 0) O02 Gla Th 8 shield Toad Ala° le oli. .1. yl. ele 1) 1 cuticular spikes 13 Rostrum narrowed O. OI 02” Oxo od Les Dee] SL ee Lele lees Le 14 Mxp syncoxa as long as or slightly shorter than basis OG. 0-= DS. ODL) Te ol Sa eT LO Leelee 1 1 15 Cphth with dorsal cuticular ridge crossed by two furrows 00001000000 0 00 0 0 0 0 0 16 1(?) Cphth laterally extended OO O20 Ot, OO: 0 LP or? 00.0: 0 On 0: Oh) - B21? 17 Cphth on lateral posterior corners with backwardly directed 0.0 20: ack GT. O 56) oO 0a D7. 10 0 08 Os GB projections 18 1st abdominal somite with small spinulose cuticular structure OO 0 *O.ec1. £0: &O OR 0: “O80” “Oye 0" _ O00 BO FQ"0 19 2™ abdominal somite with small spinulose cuticular structure OO. 0» “Ovecl- £O- BO (O8"0;° (O° 20 Oye 0 “O90. “0-80 -O. 0 20 P5 female baseoendopod and exopod fused OO. 0» “Ovenl- £0: BO O20." (O77 20" Oy = 07 0-0. “0 0: —Q: FO 21 Cphth dorsally with strong cuticular structure centrally on Ox0: TO Opal Ove LE Dv Leeds 2D. Red LP te: Te Dee es 1) posterior margin 22 Free body somites except preanal somite and telson with O10? OncO") Ove Lied pel te Les eT es ee SEL cuticular structures on posterior margin 23 Cphth dorsally with spinulose, broad projection bearing 2-4 00000211 1000000 0 0 0 0 +0 apical spikes 24 Cphth rectangular, almost square O05 O20 Or Oe sheet oe OF Oar OD, ae Oe Ade. 061 6 25 P2-bearing somite dorsally with pair of strong spikes standing O O 0 0 0141410000000 0 0 0 0 close together 26 P3-bearing somite dorsally with pair of strong spikes standing O O 0 0 0114100000 0 0 0 0 0 0 close together 2/7 P4-bearing somite dorsally with pair of strong spikes standing O O 0 0 0141410000000 0 0 0 0 close together 28 P5-bearing somite dorsally with pair of strong spikes standing O O 0 0 041414100040 0000 0 0 0 close together 29 1st abdominal somite (= posterior GDS) with dorsal sclerotized O O 0 0 0141100000000 0 0 0 clasp-like area bearing 2 spikes 30 2™ abdominal somite with dorsal sclerotized clasp-like area Q: 40> 0-079 OBL, ct-1- 5-0: 20; 050% 20" = 0: 40> 0 "0-5 O20 bearing 2 spikes 31 2 = 1% abdominal somite (= posterior GDS) withepimeres 0 0 0 0 0141ii100id1éd1édizt0 000041 extended laterally 32 3 2 abdominal somite with epimeres extended laterally 0 0 0 0 014141 #00di1idi1édift 0 0 0 0 0 1 33 Pseudoperculum developed as sclerotized clasp-like area 000001 1 1000000 0 0 0 0 0 bearing spikes 34 A2 endopodal surface seta with strongly derived tip 000003211 1 000000 0 0 0 0 0 zse.pensoft.net 252 No. 35 36 af 38 39 40 4l 42 43 44 45 46 AT 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 Tes) No. Convergences 10 11 Character/species (1 = apomorphy; 0 = plesiomorphy; 1 = supposed convergence; ? = no data available) P2 outer basal seta longer than exp-1 and exp-2, biplumose P5 baseoendopod female with 2 setae Cphth dorsal process square, spinulose, with 2 strong spikes, each outwardly accompained by 2 small ones Al female 2" segment 1 subapical outer seta remarkably elongated, longer that remaining segments together A2 endopod: surface seta comb-like at distal half; not tapering gradually P5 female baseoendopodal setae not reaching apical margin of exopod Posterior half of GDS lateral wing-like epimeres strongly pronounced 2™ abdominal somite lateral wing-like epimeres strongly pronounced Pseudoperculum consisting of paired y-shaped spikes accompanied each by single spike A2 allobasis without abexopodal seta Md palpus lost exopodal seta (= with 4 setae) Mxp syncoxa with 1 apical seta Cphth dorsal process square, spinulose, with 4 strong spikes A2 endopod seta with club-shaped, apically pinnate tip Mxl coxa with 1 apical seta MxlI basis with 1 apical seta Cphth dorsal process spinulose, elongate, with rounded apex carrying 4 spikes A2 endopod seta with square-cut, fork-like tip P3 male endopodal apophysis with indentation near its tip Cphth with single spur dorsally on posterior margin Whole body surface densely covered with fine cuticular structures Cphth laterally protruded Cphth dorsal spur broad, rather short Female GDS laterally of slightly inflated aspect Pedigerous and first 2 abdominal somites dorsally with small spiny processes on posterior margin Dense body coverage developed into tiny denticles P4-bearing somite dorsally with 4 spiny processes standing pairwise together Anterior half of female GDS with pair of spiny processes fused at their bases Posterior half of GDS and second abdominal somite dorsally with spiny processes standing close together Dense body coverage developed into short setules Cphth lateral protrusions produced into pair of narrow, backwardly directed cuticular jags Mxp strong, allobasis swollen on inner margin, claw massive, curved about 90° P3 female exp-3 with 2 outer spines P2-bearing somite with paired dorsal processes P3-bearing somite with paired dorsal processes P4-bearing somite with paired dorsal processes P5-bearing somite with paired dorsal processes P6-bearing somites with paired dorsal processes 1st abdominal somite with paired dorsal processes zse.pensoft.net Heterolaophonte minuta oO oO oOo OO Oo oOO Oo OOOO OOO Oo (jo) ©-~@ oO OOO OO Oo Coullia (jo) oOo OO Oo oOCO oO Oo OOOO OO Oo (jo) oO oO oOo OOO OO Oo Hemilaophonte janinae oO 5s (COCs) CD, -C), -C, -@' Oo OOOO OO Oo oO oO OO) OOO © Xanthilaophonte oo (jo) ors =O COO OC CO os OC O oOo O0O Oo oO oOo OOOO O-™ Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Echinolaophonte-CS Parechinolaophonte tropica @ @ ee ee O'@ ©. @. @+«@ ‘@:-O OOO: -@ oOo OO Oo | vaso Min > EER ts Ta hs en sD eb a) Pseudechinolaophonte minuta Pseudechinolaophonte veniliae Echinolaophonte armiger Echinolaophonte gladiator Echinolaophonte brevispinosa Echinolaophonte horrida Echinolaophonte oshoroensis Echinolaophonte villabonae Echinolaophonte briani Echinolaophonte hystrix Echinolaophonte tetracheir Echinolaophonte musa sp. nov. Echinolaophonte mirabilis oO oO [) oO oO oO oO oO oo oO oO » e &| Pseudechinolaophonte mordoganensis >) ay ay (>) ) ) ) () (>) oO oO oO o) ) o>) () - ay () (>) (oo) co) (>) | (=) (>) () (oe) (>) () OorRPRPrFRrFrF FF Mim: Ce Gea} Oo OOOO OO Oo Oo OOOO OO Oo oOoOCoOOoo°onN = O'@. ©: ©: :@; OF Ou.® Oo OOOO OO Oo Oo OOOO OO Oo oO OOOO OO Oo oO OOOO rF O - oO OOOO OO Oo Oo OOOO OO Oo Oo OOOO OO Oo Oo OOOO OO Oo oOo OO Oo ow - = OO Ou ok > a eo & oc +> i Fc -S sD as EP oo aK her So 3. F.C A orm Oho oS Oo eS © O14 Oo oo oO 2 ooao°o BPrPre Pr BPrPre Pr @.-2-O-9 o.0 2-8 Oooo Or Or O2O OS O.0-0 SO Ore,S (eco Mo) ot ae ooorm Oo ©o-O mm ore Ove On oo ee (a em >) One® oo oo oo cen eK em) oo oo eo: 2 O22. Oem OCOCC oO Om OOCC Oo om ome momome) © OOO 'O*ene COCO COCCOF PrPrePrFPRrFPFO PrRPrePrFPRrPF Oo PrPrePrFRrFFO PRPrPrPrRPPF Mm PrPrPrFPRrPFO PrPrPrFPrFFO ee eo) PrRPrePrFPRrPFO PrPrePrFPRrPFO Zoosyst. Evol. 99 (1) 2023, 217-252 233 No. Character/species (1 = apomorphy; 0 = plesiomorphy; Echinolaophonte-CS 1 = supposed convergence; ? = no data available) 2 ” © £ © s re a 2 o . 3 o Ss = 8 x ° w = = & 2 F,EEPEPSEEE REE Eos 2 E £#eees EBPSSESSSE RE ea Sb laee eee Sue etets Ble. Ss heen eae g SEERBEREEE Es Ee 2S S25 E 5 Sea 2858 FS SSESERSESA2RSES % s°stzsesss StSaesessse2s Z Ss ER ES ES 2 ese s Sitges oe ee ee ® a 74 2™ abdominal somite with paired dorsal processes Oy 30° VOSS “Ore, 0-2 0S) -0; 0: 0. “Oi LS. Ler) 81 eld: wel Led. 75 Cphth laterodistally extended cheek-like Oy [Gr wGr Oe OOOO eth eG “Ome sly Se 2 Oa) G2 90 76 Rostrum elongate, with rounded tip OS (0° O°" Om 0: 0""0: <0: 0: “Ou 1 Te 0, (07 +0= 0s 0 0 7/7 P3 male exopod powerfully developed OS 50% #0 2-Or OO Oe =O: m0: “Oe Is 1% 0, (07 ¥0=.:0.. 0.0 78 P3 male exp-2 outer spine massive, s-shaped QO. -G° .O°S-0- .G= "02 Oac0" Oe Othe lal 70. 0 6 O= S020 79 Tip of rostrum minutely emarginated G: -O* 25-0. G29) O50 Oe GO ede Gerba -O' 60 = SG Gag 80 Cphth: lateral “cheeks” bulging considerably G -O* <=. Oy O29) O50 ae Ome GonO 0-0" <= SG Gand 81 Rostrum basally remarkably constricted 0000000000 011000 0 0 +0 82 12 Cphth spur strongly tapering apically, apical half O. -0° -G=-O> Ot GeO OVO OOF ds AO eG 20* Oa 0 quite narrow 83 Pseudoperculum consisting of 4 tridenticulated processes Of, £0: OF l= .0 10 =-0° <0 20:7 O° 20 88 P4-bearing somite dorsal processes denticulated O =O “O° 0.20: O20. 2:0 0: 80: 'OF 11> .0 10 =-0° “0 20:7 O° 20 89 P5-bearing somite dorsal processes denticulated O =O “O° 0.20: O20. 2:0 0: 80: 'OF 11> .0 10 =-0° “0 20:7 O° 20 90 Dorsal cuticular processes of P6-bearing somite 000000000 0 01 000 0 0 0 +0 (= female anterior half of GDS) denticulated 91 Dorsal cuticular processes of 1st abdominal somite Or". Oe OOO eB OatG OF Oat: : 1 aber 0S 0, 6. (= female posterior half of GDS) denticulated 92 Dorsal cuticular processes of 2™ abdominal somite Oa OB §- OPO) Os BOS OO -0) the eo). Ue is 0 OO denticulated 93 1st abdominal somite (= posterior GDS) lateral wing-like O27 <0 "0 <0 O70: p20 20: 0: S008 OR Fie 0: ~<0> 0 S08 O20 epimeres extended completely reduced 94 2™ abdominal somite lateral wing-like epimeres extended 0000000000 0 01000 0 0 +0 completely reduced 95 14 Cphth spur laterally with tufts of long and finesetules 0 0 0 0000 00000d2é%0d1é0d1é4di1#éé441 96 P2-bearing somite with lateral cuticular processes 00000000 00 0 0100 0 0 0 +0 97 P3-bearing somite with lateral cuticular processes 0000000000 0 0100 0 0 0 +0 98 P4-bearing somite with lateral cuticular processes 0000000000 0 0100 0 0 0 +0 99 P5-bearing somite with lateral cuticular processes 000000000 0 0 0100 0 0 0 0 100 1st abdominal somite (= posterior half of female GDS) with 0.0: O° O"0 Or. 0: “0 0. -09:07-0 1° 0-0). 0° O80 0 lateral cuticular processes 101 2™ abdominal somite with lateral cuticular processes O° <0: -0.°°0:-".0. 40: 1.0" 0°) 0. 704 °0° 0° “I*- 0 «0-" 0°00: £0 102 P3 exopod male remakably strengthened OF 0°40. “0.650. 50: O50 02 *0:°°0" 0 IF" 0% 0" 0.20. *.0 FO 103 15 P3 endopod male 2-segmented Ce. O Tae 0. Oe Ole Te 2 0s Os Oe od ele lg es 1 104 16 P3 male endopod lost sexual dimorphism Oe" Ds* Pein FOe 8 Ge OF odin Oe! Died eT ee Tham 1 105 Rostrum slightly trapezoid, constricted basally and broadening O 0 0 0 0 0 000000 041d1ééd31é4i00 0 apically, rather flat/concave apical margin 106 Cphth laterally with intricate cuticular ornamentation Oy -O) 60 S200 106 OOO" Oa, Ceo en, 0> aL aed LO Ga O 107 Female GDS dorsally with cuticular “ring” OQ» -O) EO-FO, 0:02 0 0-60" 0" 00.08. sl me VL SO O-..0 108 1st abdominal somite (= posterior half of female GDS) dorsally O O 0 0 0 0 0 0 0000 041d31éd31@é+40 0 0 with strengthened, spinules-bearing cuticular area 109 2™ abdominal somite dorsally with strengthened, spinules- @: «0s © 0 eet OO: a0 HG: EO OSes = Gah Oe «ds ae Loe ete OO bearing cuticular area 110 Female pseudoperculum consisting of 2 bi- or tridenticulate O2~0r 02 021-0" 1:05 MON OF 0.0: 8 0u OL Oy See lees O80: FG processes, laterally accompanied each by 2 spikes 111 Cphth dorsal spur robust, short, with 2 dorsal notches GO 2s Se Oe: Lb OO CeO: 20. 1 ec ar? Ok 112 Cphth: lateral cuticular ornamentation considerably pronounced O O 0 0 0 00 00000 01 0 ? 0 0 0 113 Rostrum granular on anterior half GY 2 8 PO =O) kG Or Oe Gs <0 eine 0: =e 2 a r= 0 8G 114 Preanal somite with 2 spinulose rows in front of 6 26 0-0 20 £6 0 OS OC O06 els Ar 0 20 8 pseudoperculum zse.pensoft.net 234 Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Rostrum elongate, with bifurcated tip No. Character/species (1 = apomorphy; 0 = plesiomorphy; 1 = supposed convergence; ? = no data available) 2) ( c fo) Ss) fe) z 115 116 CR at least 3,5 times longer than broad 117 17 P3 outer basal seta of composite shape 118 18 P4 outer basal seta of composite shape 119 1st abdominal somite (= posterior half of female GDS): processes arising from H-like fortification 120 2™ abdominal somite: processes arising from H-like fortification 121 Pseudoperculum consisting of 4 palmate processes carrying each 5-6 “fingers” 122 Cphth lateral processes elongated, slender 123 Cphth anteriorly with moderate dorsal process 124 Cphth centrally with moderate dorsal process 125 CR at least 5,5 times longer than broad 126 Cphth lateral processes backwardly curved 127 P2-bearing somite of female: processes strongly elongate and bifurcate 128 P3-bearing somite: processes strongly elongate and bifurcate 129 P4-bearing somite: processes strongly elongate and bifurcate 130 P5-bearing somite: processes strongly elongate and bifurcate 131 P6-bearing somite: processes strongly elongate and bifurcate 132 1st abdominal somite: processes strongly elongate and bifurcate 133 2™ abdominal somite: processes strongly elongate and bifurcate 134 P2-bearing somite dorsal processes long, bearing 3 long setules basally 135 2™ abdominal somite dorsal proceses fused basally, with 2 Heterolaophonte minuta oOo OOO oO Echinolaophonte-CS 2 7) sge?2 © wn rs S SES x 5 8 8 Bf 2 2 SESS SSEL SER EG aS & 5 >RDEDSGoELCSBE SEAS =SFepoeoS Ewes SSK HERE E & 5 8 £92 6° 9 a 2 =~ SS > Sos & = S €6 { © > 8 o fF 5 S&S 2S 6 ct FEweo Serer opotE EFEoeE BV =EEgCe BS BEEE wo ERVQHeS EB = ssekfea ose SF SF SkFeteeEeseLeERVS ce Sos pes e FS FSFiSESRCELE SR CSeseess saz aes sees SSESSE RSF ERP PE SES 5s sgsgitztitseeisticss “ @seg8Hgeeegruged pa tae so" "ag 2 a Og 50 eles GP POO OO HO On OMe es OSS Lael: eek Oe" OF 507 oO: Oh. O02 SO Oe ma OOP Oe en Slee lek Oo" Oe. 50? oO. > 20-4102 0" «Os OO bre dea Oe Sle ask Gor. 80? af 0: 70. 80: =O). Or 08.00" 25 SOs. Olle a 0. De #0 wtf 50> 50.06: Ol O- "0 20) «Oy 07 02 sOa eT: 20" EO GO Oe Oa 0 Oo Os Oe One a0 ele B= 0 8 08 1s 0" =0 O02 0 OS Bie O00 8: AGO Oe 020" B05" 0! Sle 5 0% 0 Diet? 2S Ors Ge TO OO: Oita OS O90 Oe Oe Ty lL O = CieQiei? 20S OF "02 Ge. 50! O10: “Oi ONO Dee O)e Ty Orie? 2S OF SOs Ge. SO OO: = Oi Oi TO Omit Oi! TL Oh elieiO 205 OF TGs "Gs “0 WO: =O) O8 OS 0-0. AG) al onl Oe €. “0. FO D=kO= CO: «Oi ROO: = OF se O= e050 eel S50) Ote.6. 9 O""0, 20 DkO=0: 60. EO 0:10. OF. 02.0. Oi els 29 00.908 6 OO 10: "Om OO Ole O <0: 0. Ore le. O 0.7.0. 308 6-0: 0 10-6) Of One Ol* Oo <0: .0. 30rels 9 0, Ga t0e 6-0 O°: “COs Og O08 Oo <0: . 0. snl) OS 20g Bia CO GO” 0: 920-8 “ae is 0-05 CO.8: lard) (} OS SOe Brat = CRO SGT O20: 9204 *OaP Os 0-. 05 CO. 9: lal) (FOS SOe Bia OTROS GIO? 0: 92077 *Oa" Os 0-. 05 COs gel) (h OgRO yg EOC. FO a0 OO: )-0-8 “Oagiy Sy. OggOy Uses OOF aC kOe 80-05 105 0:90 "Oa FOS Or m0 Cae denticles basally and centrally, and with 2 long setules Phylogenetic relationships within Echinolaophonte Echinolaophonte_ splits into two main subordinated clades, namely the armiger—gladiator clade enclosing E. armiger and E. gladiator (Fig. 10, node N) and the brevispinosa—mirabilis clade that includes the remaining eight species (Fig. 10, node Q). The monophyly of the armiger—gladiator clade is supported by five autapomor- phies (Table 2, characters 55—59) and each species is also characterised by four autapomorphies (Table 2, charac- ters 60-67). The brevispinosa—mirabilis clade is characterised by seven unambiguous autapomorphies (Table 2, char- acters 68-74). It splits again into two subordinated clades, i.e. the brevispinosa—oshoroensis clade (Fig. 10, node R) and the villabonae—-mirabilis clade (Fig. 10, node W). Both clades are supported by four and two autapomorphies, respectively (Table 2, charac- ters 75—78 and 103, 104, respectively) and also, the relationships within the subclades can be supported by some apomorphic characters (Table 2). Within the villabonae—mirabilis clade, a further splitting took zse.pensoft.net place: the villabonae—briani clade encompasses E. villabonae and E. briani (and tentatively E. hystrix) (Fig. 10, node X), whose status as sister species is supported by six synapomorphies (Table 2, characters 105-110). Together they constitute the sister taxon of the tetracheir—mirabilis clade (Fig. 10, node AA), whose monophyly is supported by four autapomor- phies (Table 2, characters 115-118). Within the tetra- cheir—mirabilis clade, the first branch-off is FE. tetra- cheir (Fig. 10, node BB), forming the sister species of the musa—mirabilis clade (Fig. 10, node CC). All named species can be characterised by distinct autapo- morphies that are discussed in detail below. Establishment of Echinolaophonte briani Lang, 1965 Lang (1965) reported and described a new presumed subspecies from Dillon Beach, California (U.S.A.), which he named E. armiger f. briani Lang, 1965. He assumed a close relationship with E. armiger f. typica sensu Gurney (1927), but at the same time, noted some Zoosyst. Evol. 99 (1) 2023, 217-252 morphological differences that justified, in his opinion, the establishment of a new form (subspecies) briani. Based on the detailed re-description of E. armiger by Lee et al. (2006), as well as on the here presented de- tailed phylogenetic analysis, it became clear that Lang’s (1965) E. armiger f. briani in fact represents a distinct species that is closely related to EF. villabonae. Thus, it is here elevated to species rank as Echinolaophonte briani Lang, 1965. The status of Echinolaophonte hystrix and Laophonte steueri van Douwe, 1929 Echinolaophonte hystrix had been synonymised with E. armiger by Nicholls (1941) and later by Lang (1948) as Onychocamptus armiger. Lee et al. (2006) provided a well-justified re-instatement of EF. hystrix and, at the same time, recognised that Lang’s (1965) description of E. armiger f. typica (Gurney, 1927) most probably was a re-description of Brian’s (1928) E. hystrix, whose un- derlying Mediterranean material had been donated to K. Lang by A. Brian (Lang 1965: 5). The argumentation giv- en by Lee et al. (2006) is adopted here and the identity of E. hystrix is confirmed. 235 Van Douwe (1929) described another species from the French, Italian and Croatian Mediterranean coast, Laophonte steueri. That author provided a quite de- tailed textual description that lacks, however, a simi- larly detailed set of illustrations. He pointed towards the strong similarity of L. steueri with L. horrida and L. brevispinosa, apparently unaware of Brian’s (1928) description of L. hystrix. Like the latter, also L. steueri was subsequently synonymised with E. armiger by Nicholls (1941) and Lang (1948). The WoRMS data- base synonymises L. steueri with Echinolaophonte hystrix (Walter and Boxshall 2022), albeit without men- tioning the corresponding literature that might justify that synonymisation. The here presented phylogenetic analysis aimed at elu- cidating the systematic relationship of both E. hystrix and L. steueri. However, the available information is scarce and the descriptions of both species are rather imprecise and incomplete. Though, the synonymisation of L. steueri with E. hystrix is tentatively confirmed here (see Discus- sion); however and despite some indications for an allo- cation of E. hystrix into the villabonae—briani clade, due to the gap of detailed information, the systematic position of E. hystrix within Echinolaophonte remains unclear (Fig. 10, node X). Diagnostic key to the genera and species of Echinolaophonte and the here established new genera (note: E. longantennata was excluded from the analysis due to lack of data) 1 Cphth without strong, cuticular dorsal structure centrally; free body somites, except pre-anal somite and telson without well-developed cuticular StruCtures .............cceceeceeeeeeeee ees — Cphth with strong cuticular dorsal structure centrally; free body somites, except pre-anal somite and telson with well-de- VEO ISG! eM egw berry SiMe COLES wa Ree Solel 8 Sarum fete abel dee eet hatardy enue gee etcgestcle rede A gughedl a. bess glee tebtactage atte obi nsattatele heen ecabadtctee stables tele eer Mactan Naaes 3 2 P2 exp-2 with inner seta; Pl exp reaching over middle of enp.................. Parechinolaophonte tropica gen. et. comb. nov. 2 Cphth rectangular, almost square; P2—-P6-bearing somites dorsally with pair of with spikes that are basally connected to each other; A2 enp with 1 spine bearing strongly derived tip 4..............cccccccceceeeee eee ees Pseudechinolaophonte gen. nov. — Cphth not square; P2-P6-bearing somites dorsally with pair of basally separated processes instead of pair of connected spikesA2-enp without blunttip bearing. SING: G: fc. .i75se4l sme. fed ghee us ee ee eee gd eae eeU NA come ocd 8d Riad de Echinolaophonte 4 PASexp: StwitiAsetae/ SINGS: ssucecicck. ster d Paamee nes snes cinta aman eats ceekiae ees Ma ar OR Se A ee 5 — A2 enp derived seta comb-like at distal half; P4 exp-3 with 5 setae/Spines................cceeeee Ps. mordoganensis comb. nov. 5 A2 enp derived seta club-shaped; P2 exp-3 twice as long as exp-3; CR 2.0 times longer than wide Ps. minuta comb. nov. — A2 enp derived seta with a trifid tip; P2 exp-3 only slightly longer than exp-3; CR 1.5 times longer than wide................ wheat OO UAE OE Wy ocean ns Wen eee a os ae Ps. veniliae comb. nov. 6 Paired:dorsal jprocesses-tinys-cphih dorsallspur with ‘broatl| base oo i.tese cr fcoe at iyderebids vty tacdenba yxy sestedan ey Posdinnb say ydestiiauayee. Fi — Paired dorsal processes strongly developed; cphth dorsal spur with narrow DaSE ...........cccc ccc eceenec eee ee eee eeeeeeneeeeneneenenees 8 7 P&S CX PasaWiliy “SCTACHSOINES cs #44 gasietins p44 4 comma sees Eaves 88 — P3 exp-3 with 6 setae/SpINeS .............cccccececssceeeeceeeeeeeees Sena £2824! ue) be cpm rele aa Euan oa ser mem a gay als uch £8 elcome te bag E, armiger F seaag 3 iaten oe era nw wires 4 Haute te seme yng a PES gf aaR RN vethe Gmmaind HERS Fe Reon oR E. gladiator 8 Cphth laterodistally exended cheek-like; Ro elongate, with rounded tip .............cccccccecc ccc eee cee eeeeseececeeeeeeeeeeeseeeesseeneenenaes 9 — THESE Se rethee CLG: OLE OM MO NMG Ol errah tense wails x clea tubtatddeempts rabiea he teehee yecleaarts trace queue aleaeanuetie irae detest tapobacbetaneh pede a baistwee cadets Lad 9 P2-exp-s'withcinnerseta;-CR at least-2- times as. lOMBIAS. WIE: F . ti2.00088 2. Ma detsadh taasexecees Rash«madebs heceedl ec Maiedeedssipeeper see 10 — P2 exp-3 without inner seta; CR at most 2 times as ONG AS WIE ........... ec ce cece cee cec nec eeceeceeneeeeeeeceeceeseeneenees E. oshoroensis 16... Rostrumi with rounded tip: Pi-exp niet reaching, middile-of enpel.iii.as Fcc ysae ear ee or eselliea pPr enh eys E. horrida — Rostrum with bilebed dip: Plexp- reaching miuddle-ofsenped. vrccaei e.g tadeals ashe ine Seeiied Se lakes PEE ee E, brevispinosa 11 Rostrum slightly trapezoid, broadening apically; Cphth with lateral cuticular ornamentation.............ccccccccec eee eeneeeeeees 12 — Rostrum narrow and elongate; Cphth without lateral cuticular OrnaMentation ..............cccc ccc eec ccc eeceeeeeeeeeeceeceeneeneenennes 14 ee TEAS 8OK10-o ANIL eS Olle SIME Sate ahubtt 2932 het ant ck eee ee RNAs ne oI cute nh iid bom iltte Sette ie 3 bier lel ede 183 — P3 exp-3 with 6 Setae/SpINeS ............ccccccececeeceeeeeeeeeeeeeees rr rren erect tee Bethe thet at Ee och tin eelemes tees dace E. villabonae zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte 13 Female P2 enp-1 as long as enp-2; male P3 with sexual CIMOrpPhiSM...............ccccccec sec ecsceececeeceseeseceseesuceeauseneenas E. hystrix Female P2 enp-1 much shorter than enp-2; male P3 without sexual GiMOrphisM..................cccceeeeeeceeeeceeeeseeenees E. briani 14 CR at most 4 times longer than wide; female P4 enp-2 reaching beyond @xp-2 ...........ccccccecceeceeceeeeeeeen eee eeeees E, tetracheir — CR at least 5 times longer than wide; female P4 enp-2 not reaching OXP-2............ cc cecc ccc ce see neceeceeceeceeseeneeeceeceeseeneenees 15 15 P2-P6-bearing somites with strongly elongate and bifurcate processes; Rostrum without sexual dimorphism............... EP ne Ba te eee ee ee ee EL, on Be FE. musa Sp. nov. - P2-P6-bearing somites without strongly elongate and bifurcate processes; Ro with sexual dimorphism........ E. mirabilis Discussion Echinolaophonte: a systematic tangle The statement of Boxshall and Halsey (2004: 316), that the taxon Laophontidae “is a large and heterogeneous family, much in need of comprehensive revision” remains valid and is reflected even at the genus level. Therefore, the aimed phylogenetic revision of the here treated genus Echinolaophonte, which hitherto encloses 16 species (in- cluding the here described FE. musa sp. nov., E. Jonganten- nata that is excluded from our analysis and the re-instated E. briani), turned out to be a complex, sometimes confus- ing and ambitious challenge. The topic began at the end of the 18" century: Miller (1792) described a new and rare marine species from Danish and Norwegian waters: Cyclops minuticornis Muller, 1792. He provided a very brief textual descrip- tion and just one illustration of the habitus that lacks any detailed characteristics (Muller 1792: plate XIX). Subse- quently, Baird (1850) synonymised Cy. minuticornis with Canthocamptus minuticornis (Miller, 1792), reported from Berwick Bay, Dover (U.K.). He also provided only a short and imprecise textual description, mentioning, however, that the thoracic somites bear “a sharp spine” dorsally (Baird 1850: 211). His description was comple- mented by a single illustration of a lateral habitus (Baird 1850: plate XX’V, fig. 3). Claus (1863) rejected Baird’s (1850) assignment of Ca. minuticornis to Canthocamptus, substantiating it by the quite different shape of the Pl: Ca. minuticornis bears a peculiar, prehensile P1 endopod consisting of a very long enp-1 and a small enp-2, apically equipped with a strong curved claw. Such prehensile P1 is not found in Cantho- camptus. Claus (1863) established the genus Cleta Claus, 1863, however, without placing Ca. minuticornis into that taxon. This was undertaken by Buchholz (1874) as “Cleta minuticornis Miller’, who, at the same time, provided the first detailed illustrations of the lateral habitus, the cphth and first pedigerous somite, the antenna, mxp, Pl and P5 of that species (Buchholz 1874: plate XV, fig. 3). Norman (1876: 206) reported a “beautifully spinose Copepod” from a tow-net in Davis Strait (North Atlan- tic Ocean), assigning it to Buchholz’ (1874) specimen. Though, Norman (1876) doubted that this species might be the same as that which had been previously described by Miller (1792) and Baird (1850). Therefore, he pro- posed the name Cleta horrida for Buchholz’ (1874) and the Davis Street specimens. zse.pensoft.net Nowadays, Cleta is synonymised with Laophontopsis Sars, 1908 and, thus, assigned to the Laophontopsidae Huys & Willems, 1989 (cf. Huys and Willems (1989); Walter and Boxshall (2022)). In that context, it is note- worthy that, according to the WoRMS database (Walter and Boxshall 2022), Laophontopsis encloses nine species, amongst them also “L. minuticornis (Buchholz, 1874)”. However, other corresponding literature (Huys and Wil- lems 1989; Bodin 1997; Boxshall and Halsey 2004; Wells 2007) lists only three species allocated to Laophontop- sis, namely L. lamellifera (Claus, 1863) (type species), L. borealis Huys & Willems, 1989 and L. monardi Huys & Willems, 1989. To the knowledge of the authors, in the meantime, no re-evaluation of Laophontopsis has been realised. Future investigation may resolve the systemat- ics of Laophontopsis as well as the affiliation of the six additional species listed in the WoRMS database. It was Brady (1880) who removed C. horrida Norman, 1876 into Laophonte Philippi, 1840, providing an al- most complete species description of Laophonte horrida (Norman, 1876). That species was later on (partly) re-de- scribed by Sars (1908; Norway), Chislenko (1967, 1977; Franz Joseph Land, White Sea) and Kornev and Cherto- prud (2008; White Sea). Sars (1908) described a second Norwegian species that strongly resembles L. horrida: Laophonte brevispinosa Sars, 1908. So far, it is the only report of that species. Lang (1948) added the record of L. brevispinosa from the Mediterranean by Brian (1917); nevertheless, compari- son of the descriptions by Sars (1908) and Brian (1917) clearly reveals that the Mediterranean species does not belong to L. brevispinosa. The main difference between the latter and Brian’s (1917) specimen is the presence of paired dorsal processes on all free body somites, except the two last ones in L. brevispinosa (Sars 1908: pl. 168); instead, Brian’s (1917) specimen lacks dorsal processes on the pedigerous somites and bears only single processes on the remaining body somites (Brian 1917: figs 1, 2). Nineteen years after Sars (1908), Gurney (1927) de- scribed two new species from the Suez Canal (Egypt): Laophonte armiger Gurney, 1927 and L. mirabilis Gurney, 1927. Subsequent re-descriptions of both species, partic- ularly of. L. armiger, reflect the increasing confusion that finally lead to the current tangle within Echinolaophonte. Besides nomenclatoric confusion—L. armiger, for in- stance, has been alternately allocated to Laophonite, Echinolaophonte and Onychocamptus (e.g. Gurney (1927); Nicholls (1941, 1945); Lang (1948, 1965); Pesta (1959); Vervoort (1964)) — the main impediment to allow Zoosyst. Evol. 99 (1) 2023, 217-252 an unambiguous determination of the concerned speci- mens resulted from imprecise and incomplete (re-)descrip- tions and the unavailability of original material for direct comparison. In that context, especially the extraordinary and highly valuable contribution of Lee et al. (2006) has to be mentioned; these authors undertook an enormous ef- fort to clear up the systematic status of EF. armiger sensu Gurney, 1927 and, thus, started to disentangle the phylo- genetic confusion within Echinolaophonte. A further obstacle is that, since the establishment of Echinolaophonte by Nicholls (1941) and despite the in- crease of species from four to 14 until 2019, no amend- ment of Nicholls’ (1941) generic diagnosis has been pro- vided. This is particularly surprising, as several of the subsequently assigned species do not fit Nicholls’ (1941) diagnosis of the genus. As a result, Echinolaophonte be- came a heterogeneous conglomerate of species, lacking an unambiguous characterisation of the genus. Echinolaophonte was proposed by Nicholls (1941) to allocate Laophonte horrida, L. brevispinosa, L. armiger and L. mirabilis. In that context, Nicholls (1941) con- sidered two further species, L. hystrix, and L. steueri as synonyms of L. armiger (but see below). He provided a key to the four assigned Echinolaophonte species and a generic diagnosis (setation of P2—P4 omitted here): (1) cphth with single large spur on posterior dorsal margin; (II) all free body somites, except penultimate somite and telson dorsolaterally with paired processes; (III) rostrum large and expanded; (IV) female Al 6-segmented, ae on fourth segment; (V) Pl with long and slender coxa, basis and enp-1; exopod 2-segmented, short, almost reaching half the length of enp-1; (VI) female PS with narrow baseoendopod that carries four or five setae; ex- opod elongate, with three setae. As mentioned above, no amendment of the generic diagnosis has been made since then. Therefore, it is the aim of the following evaluation to provide an unambiguous phylogenetic characterisation of Echinolaophonte, with Nicholls’ (1941) generic diag- nosis as the starting basis. Phylogenetic analysis Validity of the generic diagnosis from Nicholls (1941) In a first step, the 15 species (E. Jongantennata was ex- cluded from the analysis) were examined in relation to Nicholl’s (1941) generic diagnosis, 1.e. the above listed characters I-VI. These constitute remarkable morpholog- ical deviations and, thus, are seen here as phylogenetical- ly highly relevant. Character I, presence of a single, well-developed spur on the posterior margin of the cphth (cf. Figs 9B, C): The development of a single acute spur on the posterior mar- gin of the cphth is observable in some Harpacticoida, like in the Mesocletodes abyssicola group (Argestidae Por, 1986) (e.g. Sars (1921); Lang (1948); Menzel and George (2009)). However, in the Laophontidae, that feature is Mew) absolutely rare; actually, only 11 Echinolaophonte—CS species share that peculiar deviation: EF. armiger, E. brevispinosa, E. briani, E. gladiator, E. horrida, E. hys- trix, E. mirabilis, E. musa sp. nov., E. oshoroensis, E. tetracheir and E. villabonae. The remaining four species assigned to Echinolaophonte—CS do not fit with character I. Although three species, namely E. minuta, E. mordo- ganensis and E. veniliae also present, a cuticular structure on the posterior cephalothoracic margin — which is seen here as homologous to the spur of the above listed 11 spe- cies (cf. Table 2, character 21), it is of a quite different shape, consisting of “..a Chitinous process nearly quadrangular, the posterior margin of which is provided with strong spines and many thin setae lined on dorsal surface and along margins. ”(Cottarelli and Forniz (1991: 666) (cf. Fig. 9A). That structure is interpreted here as having undergone a different further development than the single acute spur in Echinolaophonte. It is, therefore, listed as distinct apo- morphy (Table 2, character 23, see below). Finally, the last of the four species, E. tropica, presents neither a single acute spur nor a squarish spinulose and setulose structure; instead, 1t presents two dorsal furrows crossing a longitudinal cuticular ridge on its cphth (cf. Wells and Rao (1987); Ummerkutty (1970) did not pro- vide any detailed description of the cphth). Character II, presence of dorsolateral pairs of process- es on all free body somites, except penultimate somite and telson (cf. Fig. 9B, C): That character actually constitutes a character complex, as it unites all body somites, which is not applicable for all involved species. For instance, E. armiger, E. gladiator and E. tropica lack well-devel- oped dorsolateral processes on pedigerous somites P2 and P3 (cf. Fig. 9B) (E. armiger, however, presents at least very small paired socles that might be homologised with the processes found in the remaining 12 species). Moreover, E. tropica lacks dorsolateral processes on the pedigerous somites P4—P6 (anterior half of female GDS), as well as on the first (posterior half of female GDS) and second abdominal somites. Character II, a large and expanded rostrum (cf. Fig. 9C): this character is actually restricted to E. brevispinosa, E. horrida and E. oshoroensis, the remaining Echinolaop- honte—CS species bear a long, bifurcate rostrum (E. mira- bilis, E. musa sp. nov., E. tetracheir), a narrowed, rather square (FE. armiger, E. briani, E. minuta, E. tropica) or trapezoid rostrum whose anterior margin is broader than its base (E. gladiator, E. hystrix, E. villabonae) or a small rectangular rostrum (E. mordoganensis, E. veniliae). Characters IV (female Al 6-segmented), V (P1 with long and slender coxa, basis and enp-1; exopod 2-seg- mented, short, almost reaching half the length of enp-1) and VI (female PS with narrow baseoendopod that carries four setae; exopod elongate, with three setae) are con- firmed for all species. It has to be objected, however, that at least characters IV and V are not exclusively found in Echinolaophonte—CS; for instance, a 6-segmented fe- male Al (character IV) is also found in the laophontids zse.pensoft.net 238 Carraroenia McCormack, 2006, Hemilaophonte janinae Jakubisiak, 1933, Psammoplatypus Lee & Huys, 1999, Xanthilaophonte, and Coullia (part.), a Pl as described in character V is also present at least in Hemilaophonte Janinae, Xanthilaophonte and Coullia and a female P5 baseoendopod bearing four setae is also present in Hemi- laophonte janinae and Xanthilaophonte (e.g. Jakubisiak (1933); Noodt (1958); Por and Marcus (1972); Hamond (1973); Fiers (1991, 1992); Lee and Huys (1999); Gomez and Boyko (2006); McCormack (2006); Huys (2009)). Therefore, it is concluded here that, based on Nicholl’s (1941) generic diagnosis, characters I-VI are not shared by all Echinolaophonte—CS species or they are present also in other laophontid genera. Relationship of Echinolaophonte—CS with other laophontid genera In the following, a detailed character comparison is pre- sented. For that purpose, 135 morphological characters were selected (Table 2). Discussion of the membership of all here treated taxa in a monophylum Laophontidae is not an objective of the contribution at hand. Therefore, it is simply underlined by just one unambiguous apomorphy, the characteristic laophontid shape of the P1 (Table 2, character 1; Fig. 10/ Table 3: node A). For detailed discussion of laophontid systematics, see, for example, Huys (1990), Huys and Lee (1998/1999) and Lee and Huys (1999). Compared with the first outgroup Heterolaophonte minuta, a set of five apomorphies characterise Coullia, Hemilaophonte janinae, Xanthilaophonte and Echinola- ophonte—CS (Table 2, characters 2-6; Fig. 10/Table 3: node B) [plesiomorphic states in square brackets]: Character 2, female P2 endopod with at most | inner seta [with 2 setae]: whilst H. minuta retains 2 inner se- tae on the female P2 endopod, Echinolaophonte—CS and Xanthilaophonte lost 1 and Coullia and Hemilaophonte Janinae \ost both inner setae. Character 3, female P3 endopod with at most 2 inner setae [with 3 setae]: as for character 2, H. minuta retains the ancestral state of 3 inner setae, whilst Echinolaophon- te-CS and Xanthilaophonte lost | seta, Coullia lost 2 and Hemilaophonte janinae \ost all three setae. Character 4, P1 exopod at most 2-segmented [3-seg- mented]: in H. minuta the P1 presents the ancestral 3-seg- mented exopod; the exopod is (at most) 2-segmented in Coullia, Hemilaophonte janinae, Xanthilaophonte and Echinolaophonte-CS. Characters 5 and 6, Pl coxa and basis elongate and slender [coxa short, squarish or broader than long]: H. minuta presents the rather ancestral state of a short coxa and basis. In contrast, in Coullia, Hemilaophonte janinae, Xanthilaophonte and Echinolaophonte—CS, both the coxa and the basis are remarkably elongated. Characters 2—6 clearly separate the Coullia—Echino- laophonte—CS clade from Heterolaophonte minuta. It zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte remains, however, unclear, to what extent that clade con- stitutes a monophyletic unity. Other taxa like, for exam- ple, Carraroenia and Psammoplatypus, also share at least single deviations with the Coullia—Echinolaophonte—CS clade. Nonetheless, as the here presented study explicit- ly focuses on the systematic status of Echinolaophonte— CS, the expansion of the phylogenetic analysis by add- ing further supraspecific taxa is beyond the scope of the present analysis. The first branch-off from the Coullia—Echinolaophon- te—CS clade is Coullia. It differs from the Hemilaophon- te—Echinolaophonte-CS clade (Fig. 10/Table 3: node C) in the lack of the following three apomorphies (Table 2, characters 7—9): Character 7, female P3 enp-2 without outer spine [outer spine still present]: Hemilaophonte janinae, Xant- hilaophonte and Echinolaophonte-CS have lost the out- er spine on the female P3 enp-2, which is still present in Coullia. Character 8, female Al 6-segmented [at least 7-seg- mented]: Hemilaophonte janinae, Xanthilaophonte and Echinolaophonte—CS show a 6-segmented female anten- nule; the ae-bearing fourth segment is followed by 2 seg- ments only. In Coullia, all except one species also present a 6-segmented female Al (including the here exempli- fied C. tongariki). Nonetheless, as C. platychelipusoides (Noodt, 1958) still retains 7 segments in the female Al (Noodt, 1958) — the ae-bearing fourth segment followed by 3 segments, the reduction of one antennular segment in the remaining Coullia species must be regarded as fur- ther deviation within Coullia and is, therefore, interpreted here as independent and convergent development. Character 9, female P5 baseoendopod with at most 4 se- tae [with at least 5 setae]: At least C. tongariki and C. platy- chelipusoides bear five setae on the female P5 baseoendo- pod, whilst in Hemilaophonte janinae, Xanthilaophonte and Echinolaophonte—CS, only four setae are retained. The monophyletic characterisation of Coullia is not pursued here. Contrariwise, the exclusive presence of the derived characters 7-9 in Hemilaophonte janinae, Xanthilaophonte and Echinolaophonte—CS support the hypothesis of these taxa being sister groups, with charac- ters 7-9 constituting unambiguous synapomorphies. Without aiming to provide an extensive characterisa- tion of Hemilaophonte janinae, its distinct phylogenet- ic status may probably be supported by the shape, size and ornamentation of the rather short and blunt P2—P4; especially the (female) endopods stick out because of their small size that scarcely reaches the length of the respective exp-1. These derived features are missing in Xanthilaophonte and Echinolaophonte—CS and may probably build important hints for a future phylogenetic characterisation of Hemilaophonte janinae. It is, how- ever, relevant in the present context, that H. janinae lacks the supposed apomorphies 10—12 (Table 2), which are hypothesised here as synapomorphic for Xanthila- ophonte and Echinolaophonte-—CS (Fig. 10/Table 3: node D).: Zoosyst. Evol. 99 (1) 2023, 217-252 239 z oF 3 2 *Echinolaophonte-CS $ S| 3 | \ > 9g : ! 3 s @ a o 3 1 AY 1 z 8 ig 2. 1 52] i> 1 S. = i= 5 1 8 10 1 - s ‘a gs } 8 'g 3 ao] 1 2. de) 1 ae 1 m4 x< Ss ft s 1 o 2 'o i = I =s o a ' = 3 ! 7 mre i ee | | ! ' ; 3 9 Pseudechinolaophonte gen. nov. Echinolaophonte 1 : 1 1 = 9 ! I ! ! = 1 ' ! oe 2 1 t : o Se ee ees } ( - ; I I I fe] ig % I ! m f ! i 4 ! 3 IP 3 eae | 2 c ! ; ' i i Le 1 ° > 3 BY 2 A 1 a + m 1 1 1 1 = 1 : : 1 1 s. oe Lf 1 | 2 138 a 3 2 3| 3 m 3 3 Y I icf 0 = o =! f m 5 ° m m g = mt | 1 I 1 i. @ os og: im : 9 m 2 <. > O ® f | 1 i 1 iss 3 391 fl © 3 = 2 ™m S 301 1 1 ie @ 1 1 2 a ® > 5 ey) a 4 1 ; 1 1 @ a Fe tt ae: Q 9 Sg ne less > F 3 | ! os | ! 3 3 ig $ a 3 gs 7 8 3 = | = ae Pe 7 1 6 eo a : 1 1 f Vv z EE i et eee fo] [Pl Ea Ea [Z| foo] [ee | I I i) i i) Say & Oo H ' 1 os ! I I i) I I i) 1 i) I 1 i I Be G re] I I 1 I I 1 i) I I i) 1 i) 5 ue te ce] I ! I ! I ! 1 ! Poe | I I I I tf oe I i) 1 1 I ! i) I I i) i i) I I 1 I I I | I i) i) ior o I I I I i | CR ae a eed 7s SI I ? I I ! I Figure 10. Cladogram presenting the result of the phylogenetic analysis, showing the hypothesised relationships of the investigated species. The apomorphies of the nodes (A-FF) are provided in Table 3. */'chinolaophonte—CS = group of species united hitherto in the genus E'chinolaophonte. Character 10, female P4 enp-2 without outer spine [outer spine still present]: HMemilaophonte janinae still retains an outer spine on the distal endopodal segment of the P4, whereas such outer spine became lost in Xanthilaophonte and in the Echinolaophonte- CS species. Character 11, female P5 exopod with three setae [with at least four setae]: Xanthilaophonte and Echinolaophon- te-CS are characterised by a strongly reduced setation of the female P5 exopod; only three setae are present. In contrast, Hemilaophonte janinae still retains six setae on the female P5 exopod. Character 12, the presence of a peculiar pseudoper- culum dorsally on the posterior margin of the pre-anal somite [no pseudoperculum]: Hemilaophonte janinae, Coullia and Heterolaophonte minuta share a pseudoper- culum on the posterior margin of the pre-anal somite. In contrast, Xanthilaophonte and Echinolaophonte—CS de- veloped a quite peculiar pseudoperculum. It carries sev- eral digitate, cuspidate processes of high inter- and even intraspecific variability (e.g. Lang (1965); Wells and Rao (1987); Kuru et al. (2019)) and is seen here as a synapo- morphy for the respective species. From the above given comparative argumentation it 1s concluded that characters 10-12 unite Xanthilaophonte and the 15 species currently assigned to Echinolaophon- te-CS. Although not providing the complex quality of, for example, Nicholl’s (1941) characters I-VI, they are exclusive deviations of them and may, therefore, support their state as monophylum. As for Coullia and Hemilaophonte, it is neither the in- tention here to discuss the phylogenetic status of Xanthi- laophonte. In the present context, it is, however, important to assert that, apart from single supposed convergences at lower taxonomic level (cf. Table 2), Xanthilaophonte does not share the autapomorphies of the Echinolaophon- te—CS clade, as demonstrated and discussed below. The Echinolaophonte-CS clade (Fig. 10/Table 3: node E) As shown in Table 2, the 15 species remaining in the Echinolaophonte-CS group — named from now on Parechinolaophonte—Echinolaophonte clade —_ share just two exclusive deviations (Table 2, characters 13, 14): zse.pensoft.net 240 Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Table 3. List of nodes and assigned clades/taxa and apomorphies shown in Fig. 9. Presumed convergences are set in bold italics. Node Clade/taxon Included studied taxa No. apomorphies A Laophontidae all studied taxa 1 B Coullia-Echinolaophonte clade Coullia, Hemilaophonte, Parechinolaophonte gen. nov., Pseudechinolaop- 2, 3, 4, 5, 6 honte gen. nov., Echinolaophonte Cc Hemilaophonte—Echinolaophonte Hemilaophonte, Parechinolaophonte gen. nov., Pseudechinolaophonte gen. 7, 8,9 clade nov., Echinolaophonte D Xanthilaophonte-Echinolao-phonte Parechinolaophonte gen. nov., Pseudechinolaophonte gen. nov., Echinola- 10am l? clade ophonte E Parechinolaophonte gen. nov.— Parechinolaophonte gen. nov., Pseudechinolaophonte gen. nov., Echinola- 13, 14 Echinolaophonte clade ophonte F Parechinolaophonte gen. nov. Parechinolaophonte tropica gen. et comb. nov. 15, 16?, 17, 18, 19, 20, 67, 103, 104 G Pseudechinolaophonte gen. nov.- Pseudechinolaophonte gen. nov., Echinolaophonte 21,:22 Echinolaophonte clade H Pseudechinolaophonte gen. nov. Pseudechinolaophonte minuta gen. et comb. nov., Ps. mordoganensis gen. et 23, 24, 25, 26, 27, 28, 29, 30, comb. nov., Ps. veniliae gen. et comb. nov. | Pseudechinolaophonte mordoganen- Pseudechinolaophonte mordoganensis gen. et comb. nov. sis gen. et comb. nov. J Pseudechinolaophonte minuta-venilia —Pseudechinolaophonte minuta gen. et comb. nov., Ps. veniliae gen. et comb. clade nov. K Pseudoechinolaophonte minuta Pseudechinolaophonte minuta gen. et comb. nov. gen. et comb. nov. L Pseudoechinolaophonte veniliae gen. Pseudechinolaophonte veniliae gen. et comb. nov. et comb. nov. M Echinolaophonte bonae, E. briani, E. tetracheir, E. musa sp. nov., E. mirabilis N Echinolaophonte armiger—gladiator Echinocletodes armiger, E. gladiator clade Echinolaophonte armiger Echinolaophonte gladiator O Echinolaophonte armiger P Q Echinolaophonte brevispinosa— R Echinolaophonte gladiator Echinolaophonte brevispinosa, E. horrida, E. oshoroensis, E. villabonae, E. briani, E. tetracheir, E. musa sp. nov., E. mirabilis Echinolaophonte brevispinosa, E. horrida, E. oshoroensis mirabilis clade Echinolaophonte brevispinosa— oshoroensis clade S Echinolaophonte brevispinosa Echinolaophonte brevispinosa T Echinolaophonte horrida—oshoroensis Echinolaophonte horrida, E. oshoroensis clade U Echinolaophonte horrida Echinolaophonte horrida V Echinolaophonte oshoroensis Echinolaophonte oshoroensis WwW Echinolaophonte villabonae-mirabilis Echinolaophonte villabonae, E. briani, E. tetracheir, E. musa sp. nov., E. clade mirabilis X Echinolaophonte villabonae-briani Echinolaophonte villabonae, E. briani clade Y Echinolaophonte villabonae Echinolaophonte villabonae Z Echinolaophonte briani Echinolaophonte briani AA E. tetracheir—mirabilis clade BB _— Echinolaophonte tetracheir Echinolaophonte tetracheir, E. musa sp. nov., E. mirabilis Echinolaophonte tetracheir E. armiger, E. gladiator, E. brevispinosa, E. horrida, E. oshoroensis, E. villa- 31, 32, 33, 34, 35, 36, 72 37, 38, 39, 40 41, 42, 43, 44, 45, 46 47, 48, 49, 50 51, 52, 53 5A 16?, 55, 56, 57, 58, 59 60, 61, 62, 63, 103, 104 44, 64, 65, 66, 67 68, 69, 70, 71, 72, 73, 74 31, 32, 75, 76, 77, 78 79, 80 81, 82, 83, 84, 85 86, 87, 88, 89, 90, 91, 92 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 117, 118 103, 104 105, 106, 107, 108, 109, 110 67, 111, 112, 113 44, 46, 82, 95,114, 117 95, 115, 116, 117, 118 119, 120, 121 CC __Echinolaophonte musa sp. nov.— mirabilis clade DD ~— Echinolaophonte musa sp. nov. EE Echinolaophonte mirabilis Character 13, rostrum narrowed, not __ taper- ing apically [rostrum with broad base, triangular]: Hemilaophonte janinae and Coullia retain the ancestral shape of the rostrum, which consists of a broad base ta- pering apically, giving the rostrum a triangular shape. Therefore, the narrowed rostrum as present in the Pare- chinolaophonte—Echinolaophonte clade (cf. Fig. 9) 1s regarded as a deviation. A similar rostral shape, as shown for Xanthilaophonte trispinosa (Sewell, 1940) by Fiers (1991), is interpreted here as a convergence, because its congener, X. carcinicola Fiers, 1991, retains the ancestral triangular shape (Fiers 1991). Character 14, syncoxa of the mxp as long as or only slightly shorter than the basis [syncoxa reaching only zse.pensoft.net Echinolaophonte musa sp. nov., E. mirabilis Echinolaophonte musa sp. nov. Echinolaophonte mirabilis 16?, 56, 122, 123, 124, 125 126, 127,128,129) T3013]; 132,133 31 , 32, 134, 135 nearly half the length of the basis]: the species of the Parechinolaophonte—Echinolaophonte clade share the remarkable derived elongation of the maxilliped. It bears a syncoxa, a basis and an endopod produced into a long, curved claw. The syncoxa and basis are equally long and slender and the claw reaches or even surpasses the length of the basis. Instead, the maxillipedal syncoxa in Hemi- laophonte janinae and Xanthilaophonte is short (Fiers 1991, 1992). The first branch-off in the Parechinolaophonte—Echi- nolaophonte clade is Echinolaophonte tropica (Fig. 10/ Table 3: node F). That species lacks the supposed syn- apomorphies of the remaining species (Pseudechinola- ophonte—Echinolaophonte clade; see below), but can be Zoosyst. Evol. 99 (1) 2023, 217-252 characterised by six autapomorphies (Table 2, charac- ters 15—20): Character 15, cphth dorsally with cuticular ridge crossed by two furrows [without dorsal ridge and fur- rows]: Whilst the Pseudechinolaophonte—Echinolaop- honte clade bears characteristic cuticular processes on the cphth, £. tropica does not. Instead, its cphth is dorsally characterised by a kind of cuticular longitudinal ridge that is crossed by two furrows (Wells and Rao 1987). That exclusive deviation is hypothesised as an apomorphy for E. tropica. Character 16, cphth laterally extended [not extend- ed]: As indicated by Ummerkutty (1970) and further de- scribed by Wells and Rao (1987), E. tropica has a cphth that shows some exclusive deviations. Besides the dorsal cuticular ridge with furrows (character 15), the lateral margins of the cphth are remarkably extended and of tri- angular shape. Although lateral outgrowths are also pres- ent in E. mirabilis (Gurney 1927; Wells and Rao 1987) and E. musa sp. nov. (present contribution, Figs 2, 3A, 7C) and at least indicated in E. armiger (Gurney 1927; Lee et al. 2006) and EF. gladiator (Vervoort 1964), their shape differs remarkably from that in E. tropica. More- over, the latter does not share further deviations with the named species and, finally, the development of lateral processes occurs independently several times within the Harpacticoida (e.g. Cletodinae T. Scott, 1904 (part.), La- ophontodinae Lang, 1944 (part.), Idyanthidae Lang, 1944 (part.) (cf. George (2020, 2021)). Thus, their development in £. tropica is regarded here as convergent apomorphy. The possible convergent development of character 16 in the above-mentioned species is indicated by a question mark in Table 2. Character 17, cphth laterally on posterior corners with backwardly directed projections [no projections]: E. tropi- ca is the only species assigned to the Parechinolaophonte— Echinolaophonte clade that presents peculiar backwardly directed projections laterally on the posterior corners of the cphth—an unambiguous specific apomorphy. Characters 18 and 19, the presence of small spinulose cuticular structures on the posterior margins of the first and second abdominal somites [no such structures pres- ent]: E. tropica lacks the presence of paired processes on the body somites, except for the penultimate somite and the telson. Nonetheless, E. tropica indeed has small spinulose structures on the posterior margins of the first abdominal somite (posterior half of the female GDS), as well as on the second one. However, these structures differ remarkably from the paired cuspidate processes of Echinolaophonte sensu Nicholls (1941) and are, there- fore, considered as having independently evolved in E. tropica. Character 20, baseoendopod and exopod of the fe- male P5 fused: E. tropica is the only species in the Parechinolaophonte—Echinolaophonte clade, whose fe- male P5 presents a fusion of the exopod and the baseoen- dopod. In all remaining 14 species, the PS exopod and the baseoendopod are separated. The fusion is hypothesised here as clear autapomorphy for E. tropica. 241 The clear-cut characterisation of E. tropica by six autapomorphies, combined with the absence of the apo- morphies of the Pseudechinolaophonte—Echinolaophon- te clade (see below) lead to the exclusion of that species from Echinolaophonte. Instead, FE. tropica is transferred into a new genus Parechinolaophonte gen. nov. as Pa. tropica (Ummerkutty, 1970), gen. et comb. nov. (Fig. 10/Table 3: node F). The Pseudechinolaophonte—Echinolaophonte clade (Fig. 10/Table 3: node G) The remaining 14 species of the Parechinolaophonte— Echinolaophonte clade, here named Pseudechinolaop- honte—Echinolaophonte clade, share two unambigu- ous synapomorphies: Character 21, cphth dorsally with strong cuticular structure centrally on posterior margin [no cuticular structure developed] (cf. Fig. 9): All 14 species bear a strongly-developed cuticular structure posteriorly on their cphth; although the shape of that structure differs within the Pseudechinolaophonte—Echinolaophonte clade (see below), its general development is hypoth- esised here as synapomorphic for all 14 species. Fiers (1991) noted a strong morphological similarity of the ce- phalic plate in Xanthilaophonte and the juvenile cephal- ic ornamentation in certain Echinolaophonte species, which, during the ontogenesis, develop into the charac- teristic single spur present in the adults. He, therefore, postulated a close relationship between both genera. Fu- ture studies will have to shed light on the relationships of Xanthilaophonte and Echinolaophonte. Character 22, free body somites, except the pre-anal one and the telson with well-developed cuticular structures on posterior margin [no cuticular structures present]: as for the cephalothoracic dorsal structure (character 21), all 14 species of the Pseudechinolaophonte—Echinolaophonte clade bear well-developed cuticular structures on the pos- terior margins of all, except two, free body somites. Such processes are (like the dorsal process on the cphth) absent in the above treated outgroups Heterolaophonte minuta, Coullia, Hemilaophonte janinae, Xanthilaophonte and Pa. tropica gen. et comb. nov. Therefore, they are seen as an unambiguous autapomorphic character complex of the Pseudechinolaophonte—Echinolaophonte clade. Establishment of Pseudechinolaophonte gen. nov. (Fig. 10/Table 3: node H) The Pseudechinolaophonte—Echinolaophonte clade itself splits into two lineages. One lineage, enclosing Echino- laophonte minuta, E. mordoganensis and E. veniliae, can be characterised by 14 autapomorphies (Table 2, charac- ters 23-36). Twelve of them (characters 23-30, 33-36) are unique deviations of the three species, whilst char- acters 31 and 32 also arise as supposed convergences in E. brevispinosa, E. horrida and E. mirabilis. zse.pensoft.net 242 Character 23, cphth dorsally with spinulose, broad pro- jection bearing 2-4 apical teeth [no such projection] (cf. Fig. 9A): As described above for Nicholls’ (1941) charac- ter I, the peculiar structure arising on the dorsal posterior margin of the cphth of E. minuta, E. mordoganensis and E. veniliae is quite different from the single acute spur present in the remaining 11 species of the Pseudechinola- ophonte—Echinolaophonte clade. It is, moreover, unique within Laophontidae and, thus, considered here as syn- apomorphic for the three species. Character 24, cphth rectangular, almost squarish [cphth somewhat ovoid, tapering anteriorly, lateral mar- gins convex]: the outgroups Coullia, Hemilaophonte and Xanthilaophonte possess a cphth with rounded, convex lateral margins, with the posterior part being broader than the anterior one. In the Parechinolaophonte—Echinola- ophonte clade, however, the cphth underwent different morphological modifications. Echinolaophonte minuta, E. mordoganensis and E. veniliae present a clearly rect- angular cphth that is even almost squarish in shape and differs remarkably from the cphth of the remaining 11 species of the Pseudechinolaophonte—Echinolaophonte clade. This clearly different cphth is hypothesised here as a synapomorphic character of the three species. Characters 25-28, P2—P6-bearing somites dorsally with pair of strong spikes standing closely together [no paired spikes developed] (cf. Fig. 9A): E. minuta, E. mor- doganensis and E. veniliae bear strong, but narrow spikes on their free thoracic somites that differ clearly from the processes on several species of the remaining Pseudechi- nolaophonte—Echinolaophonte clade. These are seen as synapomorphic for the three species. Characters 29, 30, first and second abdominal somite with dorsal sclerotised clasp-like area bearing 2 spikes [these structures not developed] (cf. Fig. 9A): The devel- opment of such structures is unique within Laophontidae and, thus, regarded as clear synapomorphy for E. minuta, E. mordoganensis and E. veniliae. Characters 31, 32, first two abdominal somites with laterally extended epimeres [abdominal somites not ex- tended laterally] (cf. Fig. 9A): in E. minuta, E. mordogan- ensis and E. veniliae, the first (= posterior half of female GDS) and the second abdominal somites are laterally extended into flat wing-like structures. Such structures are absent in the compared outgroups, as well as in most remnants of the Pseudechinolaophonte—Echinolaophonte clade. Similar extensions are, however, also observable in E. brevispinosa, E. horrida and E. mirabilis (cf. Fig. 9C), see Discussion below). As the latter do not share further synapomorphies with E. minuta, E. mordoganensis and E. veniliae, but present derived features that are missing in E. minuta, E. mordoganensis and E. veniliae, their de- velopment of similar wing-like structures is hypothesised here as a convergent evolution. Character 33, pseudoperculum developed as sclero- tised clasp-like area bearing spikes [no clasp-like area developed] (cf. Fig. 9A): all three Pseudechinolaophonte Species are characterised by a pseudoperculum that forms zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte a Clasp-like, square area that bears several spikes. Instead, in the remaining species of Echinocletodes—CS, the pseu- doperculum consists of paired to several well-developed digitate processes arising from the distal margin. The pseudoperculum of the Pseudechinolaophonte species 1s regarded here as derived state, i.e. as synapomorphic for the three assigned species. Character 34, A2 endopod surface seta with strong- ly derived tip [element of regular bipinnate shape]: in E. minuta, E. mordoganensis and E. veniliae, one of the elements arising on the lateral margin in the distal half of the A2 endopod is remarkably transformed and presents a remarkably derived tip that even differs amongst the three species. Nonetheless, whilst all outgroup taxa, as well as Parechinolaophonte tropica gen. et comb. nov. and the remaining species of the Pseudechinolaophonte—Echino- laophonte clade, retain the ancestral bipinnate spine, the development of a strongly deviated element is considered as synapomorphic for the three species. Character 35, P2 outer basal seta longer than exp-1 and exp-2, biplumose [seta bipinnate, not reaching the distal margin of exp-2]: in E. minuta, E. mordoganensis and E. veniliae, the P2 carries an outer basal seta that is stronger and much more elongated than in all remaining here compared species. Moreover, it is biplumose, with the setules being considerably long. This is regarded as an unambiguous synapomorphy for the three species. Character 36, female P5 baseoendopod with 2 setae [baseoendopod with at least 3 setae]: in Laophontidae, the female P5 baseoendopod consists of a large, ovoid lobe representing the former endopod with five setae (e.g. Heterolaophonte minuta, cf. Willen (1992)). The endo- podal lobe becomes continuously reduced in size from Coullia via Hemilaophonte janinae and Xanthilaophonte towards the Parechinolaophonte—Echinolaophonte clade and also the number of setae decreases (Coullia: five setae, Hemilaophonte janinae, Xanthilaophonte and the Parechinolaophonte—Echinolaophonte clade: four setae). Within the latter, however, £. minuta, E. mordoganensis and E. veniliae stick out by the presence of only two se- tae. This is seen here as a clear synapomorphy for the three species. From the argumentation given above and based on the derived characters 23—36, of which the majority 1s exclu- sive to E. minuta, E. mordoganensis and E. veniliae, it is here concluded that the three species form a monophylet- ic taxon within the genus Echinolaophonte as currently composed. Nevertheless, the detected deviations shared by the three species and the recognised remarkable dif- ferences between them and the remaining 11 species of the Pseudechinolaophonte—Echinolaophonte clade led to the decision to transfer E. minuta, E. mordoganensis and E. veniliae from the Echinolaophonte—CS group into a distinct, new taxon Pseudechinolaophonte gen. nov. (Fig. 10/Table 3: node H) instead of placing them into a new subgenus. The synapomorphies of the three spe- cies, therefore, turn into autapomorphies of the new ge- nus that encloses Ps. minuta (Cottarelli & Forniz, 1991) Zoosyst. Evol. 99 (1) 2023, 217-252 gen. et comb. nov. (here designated as type species), Ps. mordoganensis (Kuru, SOnmez & Karaytug, 2019) gen. et comb. nov. and Ps. veniliae (Cottarelli, Forniz & Bascherini, 1992), gen. et comb. nov. The first branch-off within Pseudechinolaophonte gen. nov. is Ps. mordoganensis gen. et comb. nov. (Fig. 10/ Table 3: node I). That species forms the sister taxon of a minuta—venilia clade (Fig. 10/Table 3: node J) and can be characterised by four autapomorphies (Table 2, char- acters 37-40): Character 37, cphth dorsal process square, spinulose, with two strong spikes, each outwardly accompanied by two small ones [dorsal process absent or of different shape]: the cephalothoracic dorsal process is different in all three species that are so far assigned to Pseudechi- nolaophonte gen. nov. Pseudechinolaophonte mordogan- ensis gen. et comb. nov. presents a squarish sclerotised structure, covered with fine setules and bearing a pair of comparatively stronger spikes that are accompanied on their respective outer sides by two smaller spinules. This is considered as an autapomorphy for the species. Character 38, Al female second segment with one sub- apical outer seta being remarkably elongated, longer that remaining segments together [corresponding seta short]: only Ps. mordoganansis gen. et comb. nov. shows a sub- apical seta on the second segment of the female Al. It surpasses the apical edge of the last antennular segment; this is regarded as autapomorphic for the species. Character 39, A2 endopodal surface surface seta comb-like at distal half; not tapering gradually [setal tip of different shape]: as discussed for character 34, the new genus is characterised by a particular lateral spine that ends in a blunt tip; in Ps. mordoganansis gen. et comb. nov. that spine is rounded and finely serrated in its dis- tal half, presenting a somewhat comb-like shape. This is seen here as autapomorphic for Ps. mordoganensis gen. et comb. nov. Character 40, P5 female baseoendopodal setae not reaching apical margin of exopod [setae at least reaching end of exopod]: whilst in Ps. minuta gen. et comb. nov. and in Ps. veniliae gen. et comb. nov., the setae of the fe- male baseoendopod reach or even surpass the apical edge of the exopod (Cottarelli and Forniz 1991; Cottarelli et al. 1992), these setae are considerably reduced in size in Ps. mordoganansis gen. et comb. nov. (Kuru et al. 2019). That reduction is interpreted here as derived, i.e. as auta- pomorphic for Ps. mordoganensis gen. et comb. nov. The minuta—veniliae clade (Fig. 10/Table 3: node J) The minuta—veniliae clade, on its part, provides six auta- pomorphies confirming its monophyletic status (Table 2, characters 41-46). Such deviations refer to a strong pro- nunciation of the wing-like epimeres of the first two ab- dominal somites (characters 41, 42), which are only mod- erately developed in Ps. mordoganensis gen. et comb. 243 nov. Further shared deviations concern the shape of the pseudoperculum (character 43), which, in the minuta— veniliae clade, consists of a pair of Y-shaped spikes that are accompanied each by an outer single spike; in con- trast, Ps. mordoganensis gen. et comb. nov. presents a rather crown-like pseudoperculum that may vary consid- erably in shape and in the number of spikes (cf. Kuru et al. (2019)). Nonetheless, it is admitted here, that also the pseudoperculum of Ps. mordoganensis gen. et comb. nov. may constitute a deviation. However, because of the high intraspecific variability documented by Kuru et al. (2019), that feature is not considered in the present analysis. Moreover, both species share the loss of the abexop- odal seta in the A2 allobasis (Table 2, character 44) and of the exopodal seta on the mandibular palp (Table 2, character 45), which are retained, not only in Ps. mor- doganensis gen. et comb. nov., but in most of the here compared species. The loss of the abexopodal seta in the A2 allobasis has, however, also been documented for E. gladiator and E. briani (Vervoort 1964; Lang 1965). Though, as the loss of single setal elements occurs quite often and independently in Harpacticoida and because the here presented clear phylogenetic characterisation of the minuta—venilia clade, it is assumed here that the simultaneous deviation considering character 44 took place independently in both £. gladiator and E. briani and is, therefore, regarded as convergent development. Finally, the syncoxa of the mxp 1s equipped with only one instead of two setae (Table 2, character 46). The loss of one maxillipedal seta is also documented for Echino- laophonte briani;, it is seen here as convergent reduction, as the latter is embedded in a group of Echinolaophonte species that does not share the autapomorphies of Pseu- dechinolaophonte gen. nov., but is characterised by its own autapomorphies (see below). Pseudechinolaophonte minuta gen. et comb. nov. (Fig. 10/Table 3: node K) and Ps. veniliae gen. et comb. nov. (Fig. 10/Table 3: node L) can be characterised by a set of unequivocal autapomorphies (Table 2, charac- ters 47-50 and 51-53, respectively). These refer to the specific shape and ornamentation of the cephalothoracic posterior dorsal structure (Table 2, characters 47, 51; both species show considerable and quite unequal transforma- tions), the shape of the antennal derived endopodal sur- face seta (characters 48, 52; that seta is differently trans- formed in both species, cf. Table 2), the loss of one seta in the maxillular coxa and basis (characters 49, 50; only Ps. minuta gen. et comb. nov., but presumably convergent in Xanthilaophonte) and the exclusive shape of the male apophysis that presents an indentation at its tip (character 53; only Ps. veniliae gen. et comb. nov.). Revised compilation of Echinolaophonte After the above-discussed and phylogenetically justified exclusion of E. tropica, E. minuta, E. mordoganensis and EF. veniliae in combination with their transfer to zse.pensoft.net 244 Parechinolaophonte gen. nov. and Pseudechinolaophon- fe gen. nov., respectively, 11 species remain in Echino- laophonte (Fig. 10/Table 3: node M). Coming back to Nicholls’ (1941) original generic diagnoses, just these 11 Species share a main feature: Character 54, cphth with single spur dorsally on pos- terior margin [no spur developed] (cf. Figs 9B, C): the well-developed cuticular “single large recurved spur” (Nicholls 1941: 95), one main attribute of Echinolaop- honte sensu Nicholls (1941), is present exclusively in these ten species. It is regarded here as of high phylo- genetic relevance, because it is not found in any other Laophontidae (see above, discussion of Nicholls’ (1941) character I). Thus, the development of such a spur is hypothesised as an unambiguous autapomorphy for the monophylum Echinolaophonte Nicholls, 1941, compris- ing E. armiger, E. brevispinosa, E. briani, E. gladiator, E. horrida, E. hystrix, E. mirabilis, E. musa sp. nov., E. oshoroensis, E. tetracheir and E. villabonae. The armiger—gladiator clade (Fig. 10/Table 3: node N) Within that genus, two main clades are discernible. A first clade is composed of FE. armiger and E. gladiator (armiger—gladiator clade). They share five synapomor- phies (Table 2, characters 55-59): Character 55, whole body surface densely covered with fine cuticular structures [body surface smooth]: for two species, their (re-)descriptors explicitly mentioned a coverage of the whole body with “minute denticles” (Lee et al. 2006: 55, for E. armiger) or short “hairs” (Vervoort 1964: 366, for E. gladiator); such fine body ornamenta- tion has not been documented for any other Echinolaop- honte species. Although admitting that the coverage with minute cuticular elements may have been overlooked in other species, it is hypothesised here that the ornamenta- tion observed in EF. armiger and E. gladiator constitutes a synapomorphy for both species. That assumption is substantiated by the presence of characters 56-59, which also are regarded as synapomorphic for E. armiger and E. gladiator. Character 56, cphth laterally protruded [no protrusions developed]: In Echinolaophonte, the cphth, particularly its lateral margins, present a remarkable variability (see below, characters 75, 80, 106, 112, 122, 126). Echinola- ophonte armiger and E. gladiator share the development of small lateral protrusions (cf. Vervoort (1964); Lee et al. (2006)), that are absent in most remaining species of the taxon. Two further species also developed lateral pro- trusions, 1.e. E. mirabilis and E. musa sp. nov. (cf. Gur- ney (1927); Wells and Rao (1987); present contribution: Figs 2, 3A, 7A). These are, however, much more devel- oped than in E. armiger and E. gladiator, reaching their maximal size in E. musa sp. nov. Moreover, E. mirabilis and EF. musa sp. nov. share well-developed dorsal cuticular processes on the free body somites, except for the pre-anal zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte one and the telson with all remaining Echinolaophon- te species, except E. armiger and E. gladiator (Table 2, characters 68—74, see below). Therefore, the development of lateral processes on the cphth is hypothesised here as synapomorphic for E. armiger and E. gladiator, but con- vergent in comparison with E. mirabilis/E. musa sp. nov. Character 57, cphth dorsal spur broad, rather short [spur long, slender] (cf. Fig. 9B): E. armiger and E. glad- iator are characterised by a cephalothoracic spur that is compact and rather short, with a broad base, whilst the remaining Echinolaophonte species share a long and comparatively narrow process (cf. Fig. 9C). The devel- opment of a compact spur is considered here as shared deviation and, thus, as synapomorphic for E. armiger and E. gladiator. Character 58, a slight lateral inflation of the female GDS [female GDS laterally not inflated]: the female GDS of E. armiger and E. gladiator presents a some- what inflated and confluent aspect, blurring the former frontier between the original urosomites and showing its broadest extension in the area of the fusion. In contrast, in the remaining Echinolaophonte species, the previous distinction between the now fused somites remains clear- ly discernible by a remarkable lateral constriction in the area of fusion. The lateral inflation, combined with the confluent lateral borders, is seen here as synapomorphic for E. armiger and E. gladiator. A similar shape docu- mented for E. oshoroensis, Xanthilaophonte trispinosa by Fiers (1991) (but not for X. carcinicola) is regarded here as convergence. Character 59, the development of small spiny pro- cesses on the dorsal posterior margin of the pedigerous and first 2 abdominal somites [no cuticular processes developed] (cf. Fig. 9B): As discussed above, Pa. trop- ica gen. et comb. nov. does not bear any cuticular pro- jections on the dorsal posterior margin of the body so- mites. Otherwise, Pseudechinolaophonte gen. nov. and Echinolaophonte are characterised by (different) cuticu- lar structures on the respective body parts. In E. armiger and E. gladiator, these structures are developed as small spiny processes, which are hypothesised here as synapo- morphic for both species. Each species can be characterised by four autapomor- phies (Table 2, characters 60-63 and 64-67, respective- ly). In Echinolaophonte armiger (Fig. 10/Table 3: node O), the deviations refer to: Character 60, the coverage of the body with small cu- ticular denticles (cf. Lee et al. (2006)); Character 61, the presence of 4 spiny processes stand- ing pairwise together dorsally on the P4-bearing somite; Character 62, the development of a pair of spiny pro- cesses that are fused at their bases on the anterior half of the female GDS, respectively the last thoracic somite of the male (cf. Lee et al. (2006): figs 1A, 6A); Character 63, the posterior half of GDS/last thoracic somite of the male and second abdominal somite dorsally with spiny processes standing close together (cf. Lee et al. (2006): figs 1A, 6A). Zoosyst. Evol. 99 (1) 2023, 217-252 Characters 60-63 are exclusively present in E. armiger and, thus, regarded here as unambiguously autapomor- phic for that species. As indicated in Fig. 9B (exclamation mark), cuticular processes on the P2-bearing somite are apparently absent in E. armiger (cf. Lee et al. 2006). However, it is not pos- sible to determine at this point whether they are primarily absent or secondarily regressed. Therefore, this feature 1s not considered in the analysis. On the other hand, E. gladiator (Fig. 10/Table 3: node P) is characterised by: Character 64, the coverage of the body with fine set- ules (“hairs”) instead of small denticles; Character 65, the cephalothoracic lateral protru- sions produced into pair of narrow, backwardly directed cuticular jags; Character 66, the remarkable transformation of the mxp into a strong appendage whose allobasis is swollen on its inner margin and the endopodal claw being massive and curved about 90°: Character 67, the (female) P3 exp-3 with only two out- er spines (cf. Vervoort (1964)). Character 67 is also observable in Xanthilaophonite, Parechinolaophonte tropica gen. et comb. nov. (cf. Fiers (1991); Ummerkutty (1970); Wells and Rao (1987)) and in Echinolapohonte villabonae (cf. Fuentes-Rein- és and Suarez-Morales (2017)). Nevertheless, as dis- cussed above, the former branched off much earlier and Pa. tropica gen. et comb. nov. is characterised by six autapomorphies (Table 2, characters 15—20), whilst E. villabonae belongs to a well-supported monophylum with the remaining Echinolaphonte species (see below). The loss of one outer spine in both species is, therefore, seen as convergence. The brevispinosa—mirabilis clade (Fig. 10/ Table 3: node Q) The remaining clade, here named brevispinosa—mirabilis clade, encloses nine species. It is unambiguously support- ed by seven autapomorphies (Table 2, characters 68-74). The deviations apply to the development of dorsal pro- cesses on all free body somites, except the pre-anal one and the telson (cf. Fig. 9C). The processes show a con- siderable variability in the different species. Nonetheless, particularly those of the thoracic somites differ remark- ably from the spikes observable in Pseudechinolaophon- te gen. nov., being stronger, often spinulose and basal- ly accompanied by two sensilla (e.g. Sars (1908); Lang (1965); It6 (1969); Mielke (1981); Fuentes-Reinés and Suarez-Morales (2017); present contribution: Figs 2, 3A, 7C, 8C). The development of such cuticular structures is hypothesised here as synapomorphic for all remaining nine Echinolaophonte species, supporting so their mono- phyletic character. The brevispinosa—mirabilis clade divides again into two clades, namely the brevispinosa—oshoroensis clade 245 (three species) and the villabonae-mirabilis clade (six species). These clades are characterised by four and two autapomorphies, respectively. The brevispinosa—oshoroensis clade (Fig. 10/ Table 3: node R) The species united in the brevispinosa—oshoroensis clade share — besides the supposed convergently developed characters 31 and 32 — four unique characters (Table 2, characters 75—78) that enable the confirmation of a mono- phyletic group: Character 75, the lateral cheek-like extension of the cphth [lateral margins of cphth different]; whilst the species pooled here to Pseudechinolaophonte gen. nov. present an almost squarish cphth and that of Parechi- nolaophonte tropica gen. et comb. nov. displays unique deviations, the cphth of the Echinolaophonte species presents three main variations: (a) the development of lateral protrusions like in £. armiger and E. gladiator and presumably convergent in E. mirabilis and E. musa sp. nov. (Table 2, character 56; cf. discussion above), (b) The formation of a bulbous, so-called “intricate cuticular or- namentation” (Fuentes-Reinés and Suarez-Morales 2017: 22) on the distal half of the cphth (Table 2, character 106, see Discussion below) and (c) the cphth being cheek-like extended laterally on its distal half (character 75). Such kind of extension is shared by the species assigned here to the brevispinosa—oshoroensis clade. It gives the respec- tive species a kind of “chubby cheek”-like aspect in the dorsal view and is clearly noticeable in E. brevispinosa and EF. horrida (cf. Sars 1908, plates 166-168), as well as in E. oshoroensis (cf. It6 (1969), fig. 6.1). This later- al convexity is regarded here as synapomorphy for the named three species. Character 76, rostrum elongate, with rounded tip: All three species present a rostrum of a peculiar shape (Sars 1908, plates 166-168; It6 1969, fig. 7.1). It is remarkably elongated and divided into a proximal half that is sclero- tised, laterally constricted, but broadening distally. The pair of sensilla arises laterally at the broadest area. The distant half is rather soft, reaching almost the length of the proximal half and ending in a rounded tip. The shape of the rostrum is unique within Echinolaophonte and is hypothesised as synapomorphic for E. brevispinosa, E. horrida and E. oshoroensis. (see Discussion of charac- ter 13 for Xanthilaophonte). Characters 77, 78, the male P3 exopod is powerfully developed (character 77) and bears on its exp-2 a mas- Sive, S-shaped outer spine (character 78): the strengthen- ing of the P3 and P4 exopods seem to form part of a sex- ual dimorphism in Echinolaophonte. In E. brevispinosa, E. horrida and E. oshoroensis, particularly the P3 exopod suffers a remarkable strengthening as compared to the fe- male (Sars (1908) plates 166-168; Itd (1969), fig. 9.3). Moreover, the outer spine of the P3 exp-2 is robust, com- paratively short and curved outwards, reminding weakly zse.pensoft.net 246 of an “s”. Both characters are seen here as clearly synapo- morphic for the three species. Echinolaophonte brevispinosa (Fig. 10/Table 3: node S) is the first branch-off in the brevispinosa—oshoroensis clade and is considered the sister taxon of a horrida—osho- roensis Clade. Its distinct phylogenetic state is supported by 2 supposed autapomorphies (Table 2, characters 79, 80): Character 79, the emargination of the rostral tip: the rostral tip is rounded regularly in E. horrida and E. oshoroensis, but presents a narrow, but distinct emargination in E. brevispinosa, which is considered as a deviated feature and, thus, as autapomorphic for the latter. Character 80, the considerable bulging of the cepha- lothoracic lateral “chubby cheeks”: the lateral “cheeks” present their strongest expression in E. brevispinosa (Sars (1908), plate 168) and is considered as autapomorphic for the species. The horrida—oshoroensis clade (Fig. 10/Table 3: node T) The monophyly of the horrida—oshoroensis clade is sup- ported by five autapomorphies (Table 2, characters 81—85).: Character 81, lateral constriction of the rostral proxi- mal half considerably pronounced; Character 82, cephalothoracic spur elongated, surpass- ing posterior margin of cphth; Character 83, pseudoperculum consisting of 4 tri-den- ticulated processes (cf. Fig. 9C); Character 84, Pl exopod diminished in length, not reaching half the length of enp-1; Character 85, male P3 enp-2 apophysis with acute jag basally on inner margin. In E. brevispinosa, the lateral margins of the ros- trum are constricted, but much less than in E. horrida and E. oshoroensis (character 81); the spur on its cphth is small and does not surpass the posterior margin (Sars 1908: plate 168), whilst the spur of £. horrida and E. os- horoensis clearly surpasses the posterior margin of the cphth; moreover, it tapers remarkably, presenting a quite narrow distal half (character 82) (Sars (1908): plate 166; It6 (1969): figs 6.1, 6.2); the pseudoperculum of EF. bre- vispinosa consists of only two tri-denticulated processes that are accompanied by three single spikes on their outer sides (character 83) (Sars (1908): plate 168). Admittedly, this character remains somewhat vague, because also the peculiar pseudoperculum of £. brevispinosa may consti- tute an apomorphic feature. Here it 1s, however, assumed that the single outer spikes found in the pseudoperculum of E. brevispinosa may have fused together in the last common ancestor of FE. horrida and E. oshoroensis, form- ing the outer tri-denticulate processes as found in these species. In E. brevispinosa, the P1 exopod — in particular the exp-2 — is long and still surpasses the length of the P1 enp-1 (character 84). In contrast, the diminution of the P1 exopod has progressed, resulting in an exopod whose length barely reaches 1/3 of the length of the enp-1; as zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte shown by Sars (1908: plates 166, 167) and It6 (1969: fig. 9.3), both species bear an acute jag basally on the inner margin of the apophysis in the male P3 enp-2 (character 85). That jag is absent in E. brevispinosa (Sars (1908): plate 168). Basing on the description of Sars (1908) and the re-de- scription of Kornev and Chertoprud (2008), E. horrida (Fig. 10/Table 3: node U) can be characterised by seven autapomorphies: the dorsal cuticular body processes are equipped with several fine spinules (Table 2, characters 86—92). In contrast, both E. brevispinosa and E. oshoroen- sis lack such spinulose coverage, retaining the original bare setae. Therefore, the development of fine spinules on the cuticular body processes is hypothesised here as autapomorphic for £. horrida. In contrast, E. oshoroensis (Fig. 10/Table 3: node V) presents ten morphological deviations, here hypothesised as specific autapomorphies (Table 2, characters 93-102): Characters 93, 94, secondary loss of the wing-like lat- eral epimers: As explained in the discussion of features 31 and 32, lateral wing-like epimeres are considered to have arisen convergently on the first two abdominal seg- ments on three occasions: once in Pseudechinolaophonte, once in E. mirabilis and once in the brevispinosa—osho- roensis clade. While E. brevispinosa and E. horrida re- tained the epimeres, they were secondarily reduced again in E. oshoroensis. This hypothesis is based on the fact that E. horrida and E. oshoroensis are well justifiable as sister-groups on the basis of synapomorphies 81 to 85, whereas neither species shares exclusive derived char- acters with E. brevispinosa. Only the presence of lateral epimers could be an indication of a closer relationship between E. brevispinosa and E. horrida, which, howev- er, led to the not very plausible assumption that the com- mon derived characters of E. horrida and E. oshoroensis would have to be interpreted as convergences in return. A secondary reduction of the wing-like epimeres in E. osho- roensis, therefore, seems the most plausible and parsimo- nious explanation. Character 95, Cphth spur laterally with tufts of long and fine setules: A very similar kind of process has also been observed in Echinolaophonte briani, E. tetracheir (only textual description by Mielke (1981): 53), E. mira- bilis and E. musa sp. nov. (cf. Lang (1965): fig. 280a, c; described as E. armiger f. typica; Mielke 1981; Mielke (1981); Wells and Rao (1987); present contribution; see below). However, E. briani lacks apomorphic characters 75-78 of the brevispinosa—oshoroensis clade, but shares characters 103 and 104 with £. villabonae, E. tetracheir, E. mirabilis and E. musa sp. nov. (see below). Nonethe- less, as the close relationship between FE. oshoroensis and EF. horrida seems to be well-founded by shared apo- morphies 81-85, likewise, the support of a close rela- tionship of both species with E. brevispinosa (characters 75-78), the expression of a similar cephalothoracic spur in E. briani is interpreted here as convergent evolution. Characters 96-101, presence of lateral cuticular pro- cesses from the P2-bearing somite to the second abdominal Zoosyst. Evol. 99 (1) 2023, 217-252 somite: Echinolaophonte oshoroensis is the only species bearing additional lateral cuticular processes on the body somites, except the pre-anal one and the telson (It6 1969). This derived condition is regarded as autapomorphic for E. oshoroensis. Character 102, the male P3 exopod remarkably strengthened: The powerful development of the male P3 exopod (character 78, see above) is further strengthened in E. oshoroensis, having been developed into a massive and broad appendage (Itd 1969: fig. 9.3), which is unique within Echinolaophonte. The villabonae—mirabilis clade (Fig. 10/Table 3: node W) The supposed sister group of the brevispinosa—oshoroen- sis Clade is composed of six species, namely E. villabo- nae, E. briani, E. hystrix, E. tetracheir, E. musa sp. nov. and E. mirabilis. These are united into the villabonae— mirabilis clade and share the following two apomorphic characters related to the shape of the male P3 (Table 2, characters 103, 104): Character 103, male P3 endopod 2-segmented [endo- pod 3-segmented]: The Laophontoidea present a 3-seg- mented male P3 endopod that is sexually dimorphic, with the enp-2 bearing a well-developed apophysis on its apical outer margin; this is considered as autapomorphy for the Laophontoidea (e.g. Huys (1990), Huys and Lee (1998/1999)) and retained in almost all laophontid spe- cies, so is the ground-pattern of Echinolaophonte. How- ever, the six species pooled into the villabonae—mirabilis clade share the derived state of the reduction of 1 endop- odal segment. Character 104, male P3 endopod lost sexual dimor- phism [male P3 endopod sexually dimorphic]: The loss of a pronounced sexual dimorphism in the male P3 endopod is presumably linked with the reduction of 1 segment. Like character 103, it is a clear deviation as compared with the remaining Echinolaophonte species. Remarks: It is assumed here that, during the ontoge- netic development, the formation of the second segment, which carries the apophysis in the adult male, has been suppressed. However, compared with Huys’ (1990) hy- pothesis regarding the development of the male P3 endo- pod, the conditions observed in the vi/labonae-mirabilis clade are not yet fully understood. Here, a detailed de- scription of juvenile stages is necessary. As mentioned in the Introduction, the loss of the sexual dimorphism has been regarded as an important phylogenetic feature by several authors (e.g. Lang (1965); Mielke (1981); Cot- tarelli and Forniz (1991); Kuru et al. (2019)). Neverthe- less, the character matrix (Table 2) reveals that charac- ters 103 and 104 distribute somewhat heterogeneously over the different taxa that are otherwise well-justified by other supposed apomorphies. Therefore, although it is on the one hand observable that the reduction of one endopodal segment in the male P3 seems to be linked 247 unquestionably to the loss of the sexual dimorphism, one may, on the other hand, see that such loss occurs in quite different taxa like Xanthilaophonte, Parechinolaophonte gen. nov., E. armiger and the villabonae—-mirabilis clade. Uniting all these different taxa because of their collective loss of the sexual dimorphism in the male P3 would re- sult in incongruencies with respect to many other derived characters that clearly separate them. Consequently, it is hypothesised here that the simultaneous loss of the sexual dimorphism on the male P3, combined with the loss of one endopodal segment in the above-named taxa, is due to convergent development. The villabonae—mirabilis clade divides into two mono- phyletic taxa, each characterisable by distinct autapomor- phies: the villabonae—briani clade (Table 2, characters 105-110) and the tetracheir—mirabilis clade (Table 2 characters 115-118). o) The villabonae—briani clade (Fig. 10/Table 3: node X) The villabonae—briani clade is characterised by the following derived features provided by FE. villabonae, E. briani and E. hystrix: Character 105, rostrum slightly trapezoid, constricted basally and broadening apically, with rather flat/concave apical margin, distal half smooth: with a basal constriction and a soft distal part, the shape of the rostrum in E. briani (Lang (1965): fig. 280b), E. hystrix (Brian (1928): fig. 131) and EF. villabonae (Fuentes-Reinés and Suarez-Morales (2017): figs 1D, 2B) reminds us on the rostrum of the brevispinosa—oshoroensis clade; however, without the rounded extension of the distal half. Compared with ear- lier branch-offs like, for example, Pseudechinolaophonte gen. nov., Echinolaophonte armiger and E. gladiator, the rostrum observed in the villabonae—briani clade is seen here as a shared deviation of the enclosed species. Character 106, cphth laterally with intricate cuticu- lar ornamentation: EF. villabonae, E. briani and E. hys- trix share the peculiar cuticular ornamentation along the extended laterodistal margin of the cphth (Lang (1965): fig. 280c; Fuentes-Reinés and Suarez-Morales (2017): fig. 1D). This feature is unique within Echinolaophonte. Character 107, the female GDS dorsally with cuticular “ring”: Both Lang ((1965): figs 280e, 284c) and Fuen- tes-Reinés and Suarez-Morales ((2017): fig. 1E) doc- umented what Lang (1965: 509) described as “conical elevation, in dorsal aspect giving impression of a ring”. That structure is located dorsally on the border between the anterior and the posterior halves of the female GDS. It is exclusively present in the villabonae—briani clade. Characters 108, 109, posterior half of female GDS and second abdominal somite dorsally with strength- ened, spike-bearing cuticular process: such structure is only present in the vil/labonae—briani clade. Superficially, in dorsal view, it may resemble the respective cuticular structures described for Pseudechinolaophonte gen. nov. zse.pensoft.net 248 (Table 2, characters 29, 30), but, whilst these represent squarish, clasp-like spinulose areas bearing two strong spikes, the processes in the villabonae—briani clade pres- ent several strong spinules on their posterior margins (cf. Lang (1965); Fuentes-Reinés and Suarez-Morales (2017)). Character 110, the female pseudoperculum consisting of two bi- (or tri-)denticulate processes, laterally accompa- nied each by two spikes: As already mentioned (cf. discus- sion of characters 43, 83), the shape of the pseudoperculum is, either intra- and interspecific, highly variable. Other- wise, as discussed above for Pseudechinolaophonte minu- ta gen. et comb. nov. and Ps. veniliae gen. et comb. nov. (character 43), respectively for Echinolaophonte horrida and E. oshoroensis (character 83), supposed closely-re- lated species can be characterised by an almost identical shape of the pseudoperculum, supporting that close rela- tionship. This applies also to E. villabonae, E. briani and E. hystrix, whose pseudoperculum is almost identical in shape, but differs from that of all remaining species under consideration. Thus, it is seen here as a common deviation. Echinolaophonte villabonae (Fig. 10/Table 3: node Y) can be characterised by three autapomorphies (Table 2, characters 111-113). It presents its cephalothoracic dor- sal spur robust, short, with two dorsal notches (char- acter 111); the lateral cuticular ornamentation is con- siderably pronounced (character 112); its rostrum is granular on apical half (character 113) (cf. Fuentes-Rein- és and Suarez-Morales (2017)). The supposed sister tax- on £. briani lacks all these features; as mentioned above (characters 82, 95), that species bears a dorsal spur on the cphth that reminds us on that of E. oshoroensis, which is also seen as specific (and convergent) autapomorphy; the ornamentation along the lateral margins of the cphth are clearly discernible, but much less pronounced than in E. villabonae;, the rostrum of EF. briani lacks the granular shape on its apical half. Echinolaophonte briani (Fig. 10/Table 3: node Z) is characterisable by one autapomorphy (Table 2, character 114). It is the only representative of Echinolaophonte that bears two rows of spinules running parallel and longitu- dinally in front of the pseudoperculum on the pre-anal so- mite. Furthermore, the A2 allobasis lacks an abexopodal seta (character 44) and the syncoxa of the mxp bears only one apical seta (character 46). The latter two deviations are, however, hypothesised as convergent developments, as they are also present in Pseudechinolaophonte minuta and Ps. veniliae (see above). Remarks: from the descriptions by Brian (1928) and van Douwe (1929), it can be concluded that LZ. hystrix and L. steueri, in fact, stand in close relationship with E. villabonae and E briani. They share synapomorphies 105-110. Character 107, i.e. the cuticular “ring” on the female GDS, was described for EF. hystrix by Lang (1965) as E. armiger f. typica, but was neither textually described nor illustrated by Brian (1928) and van Douwe (1929) and the textual description of the shape of the pseudoperculum of L. steueri (character 110) given by van Douwe (1929) is too imprecise for comparison. However, the pseudoper- zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte culum shown in van Douwe’s (1929) fig. 18 indicates the similarity with the corresponding structure present in E. villabonae and E. briani. However, as documented by Lang ((1965): figs 284c—e), the inter- and even intraspe- cific variability seems not to be insignificant. Therefore, character 110 should be interpreted with caution. Direct comparison of the species reveals that, in L. steueri, the posterolateral cuticular ornamentation on the cphth is as strongly pronounced as in E. villabonae. Otherwise, L. steueri shares an almost identical cephalo- thoracic dorsal spur with E. briani, although van Douwe (1929) did not mention any setular tufts. Moreover, as discernible from van Douwe’s (1929) fig. 18, the preanal somite seems to bear spinules — perhaps in 2 rows — in front of the pseudoperculum. Due to these similarities and because both Brian (1928) and van Douwe (1929) found their species in the same location (Rovigno, Croatia) or close geographical surroundings (the coast between Italy and France), L. steueri is synonymised here with E. hys- trix. Nevertheless, as both species are imprecisely and/ or incompletely (re-)described (Brian 1928; van Douwe 1929; Lang 1965) and, thus, inhibit a detailed comparison, the systematic position of £. hystrix within the villabonae— briani clade can be only tentative (cf. Fig. 10, dotted line). The tetracheir—mirabilis clade (Fig. 10/Table 3: node AA) That clade encloses the species Echinolaophonte tetra- cheir, E. musa sp. nov. and E. mirabilis. Within Echinola- ophonte, they share the following four synapomorphies: Character 115, an elongated rostrum with a bifurcat- ed tip: although the development of an elongated, bi- furcated rostrum is also present in other Harpacticoida (e.g. Ancorabolus Norman, 1903 (Ancorabolidae Sars, 1909), Pseudechinopsyllus George, 2006, Pseudopoly- ascophorus George, 2021 (Cletodinae T. Scott, 1904)), in Laophontidae, only the representatives of the tetra- cheir—mirabilis clade show that derived development. It is hypothesised here as synapomorphic for the en- closed species. Character 116, CR at least 3.5 times longer than broad: the caudal rami of the here treated outgroups, as well as of the other here treated taxa are short, reaching most- ly twice the length of their broadest width. Instead, the tetracheir—mirabilis clade displays caudal rami that are clearly elongated and slender. This is regarded as autapo- morphic for that clade. Characters 117, 118, outer basal seta of P3 and P4 of composite shape: The development of composite setae in the bases of the P3 and P4 is not common within Laophon- tidae, as observable, for example, in the here treated out- groups Heterolaophonte minuta, Coullia, Xanthilaophonte and Hemilaophonte janinae. (Fiers 1991, 1992; Willen 1992; Gomez and Boyko 2006). A composite seta is also missing in Pseudechinolaophonte gen. nov. (e.g. Cottarelli and Forniz (1991); Kuru et al. (2019)). For Parechinola- Zoosyst. Evol. 99 (1) 2023, 217-252 ophonte tropica gen. et comb. nov., however, Wells and Rao (1987: fig. 144d—f) illustrated bi-articulated outer bas- al setae in P2—P4. Due to the relatively large phylogenetic distance between Pa. tropica and the tetracheir-mirabilis clade evidenced in the present work, a convergent evo- lution of the composite setae can, however, be assumed. After all, the first articulation is very small in Pa. tropi- ca, whilst it is particularly long in the tetracheir—mirabilis clade, occupying half of the total setal length. In Echinola- ophonte, an elongated composite seta is also present in the P3 basis of FE. oshoroensis and E. briani; the former bears a composite seta also on the basis of the P4. This sporadic development is a clear indication for the convergent forma- tion of composite setae; nonetheless, as characters 117 and 118 are present in all three species of the tetracheir—mira- bilis clade, it is assumed here that a composite seta may have evolved in the P3 and P4 of the last common ancestor, thus constituting a synapomorphy for the three species. The first branch-off within the tetracheir—mirabilis clade is Echinolaophonte tetracheir (Fig. 10/Table 3: node BB). It has three morphological deviations, here consid- ered as autapomorphies (Table 2, characters 119-121): in the first abdominal somite (posterior half of female GDS) and the second abdominal somite, the cuticular process- es arise from cuticular fortifications that are of a H-like shape (characters 119, 120), 1.e. they do neither form a clasp-like area as in Pseudechinolaophonte gen. nov. (cf. characters 29, 30) nor strengthened squarish spinulose ar- eas like in the vi/labonae—briani clade (cf. characters 108, 109). Furthermore, the pseudoperculum of E. tertacheir consists of four palmate processes carrying four to seven finger-like spinules with slightly rounded tips (character 121); it was that special shape of the pseudoperculum that prompted Mielke (1981: 59) to give the specific epitheton tetracheir. It differs remarkably from the pseudopercu- la of E. musa sp. nov. (two central processes with three to four acute spinules, accompanied each at its outside by a smaller process with several fine spinules apically; cf. Fig. 8F) and E. mirabilis (four processes ending each in two to three acute spinules; cf. Wells and Rao (1987: fig. 140g); not documented by Gurney (1927)). The musa—mirabilis clade (Fig. 10/Table 3: node CC) The remaining musa—mirabilis clade presents four derived characters (Table 2, characters 122—125) that are seen here as synapomorphies of E. musa sp. nov. and E. mirabilis: Character 122, cphth laterally with long and slender processes: both species present remarkably long and slen- der lateral processes on the cphth. Their development is unique not only within Echinolaophonte, but also in La- ophontidae and, therefore, considered as synapomorphic for E. musa sp. nov. and E. mirabilis. Characters 123, 124, cphth equipped with a further anterior and central cuticular process: Besides the dorsal spur that is characteristic for Echinolaophonte, E. musa 249 sp. nov. and E. mirabilis bear two further structures dor- sally on the cphth. Behind the rostral area and in the centre of the cphth, two moderate spurs arise (Gurney (1927): figs 162C, D; present contribution, Figs 2, 7A). Their exclusive development in these species leads to the assumption of their synapomorphic characteristic. Character 125, CR at least 5.5 times longer than broad: Echinolaophonte musa sp. nov. and E. mirabilis are the only species within Echinolaophonte, whose caudal rami are remarkably elongated, reaching a length/width ratio of > 5:1. This is regarded as synapomorphic for both species. The here described Echinolaophonte musa sp. nov. (Fig. 10/Table 3: node DD) presents a rich set of morphological deviations, ranging from a general somewhat “haggard” body shape, the extreme elongation of the rostrum and CR, to the special shape of the dorsal body processes (cf. Figs 2, 3A, 7C). For the here presented phylogenetic analysis, eight clear deviations were selected (Table 2, characters 126-133); they unambiguously support the characterisa- tion of E. musa sp. nov. as a distinct taxon. Character 126 refers to the lateral processes on the cphth; these are re- markably elongated and curved backwardly. Such lateral processes are unique in Echinolaophonte. The same applies to the following characters 127-133. These consider the shape and size of the particular free body somites, which are remarkably elongated in comparison with all remain- ing Echinolaophonte species. Moreover, the processes end in bifurcated tips, which is also an exclusive characteris- tic within Echinolaophonte. Thus, by means of characters 126-133, the establishment of a new species Echinolaop- honte musa sp. nov. 1s well-supported and doubtless. In contrast, a clear-cut characterisation of E. mirabilis (Fig. 10/Table 3: node EEF) 1s difficult. This is due to the fragmentary description provided by Gurney (1927), as well as to the somewhat imprecise and confusing re-de- scription given by Wells and Rao (1987). The latter dis- posed of the type material plus a single male and female specimen collected from the Andaman Islands (Wells and Rao 1987). Whilst being convinced that the Andaman male belongs to £. mirabilis, Wells and Rao (1987) were sceptical with respect to the Andaman female that showed several differences compared to the female holotype. Unfortunately, the authors desisted from re-describing E. mirabilis, based on the female holotype. As a result, no detailed description of E. mirabilis is available, whilst the (also incomplete) description of the Andaman female tended to increase confusion rather that resolving it. However, based on particular re-described body parts provided by Wells and Rao (1987), two potential autapo- morphies were detected to characterise E. mirabilis: Character 134, the dorsal processes on the P2-bearing somite dorsal processes being long, bearing three long setules basally: no other Echinolaophonte presents such dorsal processes (cf. Wells and Rao (1987): fig. 140a), which are, therefore, regarded as exclusive deviation in E. mirabilis. Character 135, the dorsal processes on the second abdominal somite are fused basally, with two denticles zse.pensoft.net 250 basally and centrally and with two long setules: As for the previous character, also these processes are unique in Echinolaophonte. Remarks on previous findings of E. mirabilis in Asia Amongst the congeners of the Echinolaophonte complex, two Echinolaophonte species were reported from Asia: E. oshoroensis from Japan (It6 1969) and E. mirabilis from China (Zhang and Li 1976) and Korea (Kim 2013). Zhang and Li (1976) recorded 20 harpacticoid copepods belong- ing to 11 families, including the then new species Eupelte acutispinis Zhang & Li, 1976 (Peltidiidae Claus, 1860) from Xisha Island, China. They listed the species name Onycho- camptus mirabilis (= E. mirabilis) without any information (e.g. sex, number of specimens, figures, short descriptions etc.). Recently, Kim (2013) reported E. mirabilis from Jeju Island (Korea) amongst 40 harpacticoid species belonging to 13 families. He found the Echinolaophonte specimens at Sungsanpo, a locality that is situated close to the type local- ity of E. musa sp. nov. Nevertheless, Kim’s (2013) infor- mation on the reported species 1s quite rudimentary, provid- ing only short diagnoses and few photographic images. To clarify the identity of the Korean Echinolaophonte species, we re-examined the specimens deposited by Kim (2013) at the National Marine Biodiversity Institute of Korea (reg. no. MADBK 721114-001). After careful re-examination we confirmed that the specimens, in fact, represent the new species E. musa sp. nov., not E. mirabilis. Conclusions The description of a new laophontid species from Jeju Island (Korea) and the subsequent attempt to allocate it to Echinolaophonte Nicholls, 1941 (Copepoda, Harpac- ticoida, Laophontidae T. Scott, 1904) revealed that this genus actually constitutes a heterogeneous conglomerate of species that cannot be united by means of clear-cut synapomorphies. Therefore, an exhaustive phylogenetic analysis of Echinolaophonte was undertaken, based on 135 morphological characters. Until the here presented phylogenetic re-evaluation, the genus enclosed 14 spe- cies. The phylogenetic analysis resulted, however, in the exclusion of four species from Echinolaophonte: E. tropica Ummerkutty, 1970, was assigned to Parechinolaophonte gen. nov. as Pa. tropica (Ummer- kutty, 1970) gen. et comb. nov.; the three Mediterranean species FE. minuta Cottarelli & Forniz, 1991, £. mordo- ganensis Kuru, Sonmez & Karaytug, 2019 and E. venilia Cottarelli, Forniz & Bascherini, 1992 were allocated to Pseudechinolaophonte gen. nov. as Ps. minuta (Cottarel- li & Forniz, 1991), gen. et comb. nov., Ps. mordoganen- sis (Kuru, Sonmez & Karaytug, 2019), gen. et comb. nov. and Ps. venilia (Cottarelli, Forniz & Bascherini, 1992), gen. et comb. nov. Both new genera are characterised zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte by exclusive autapomorphies. Echinolaophonte longan- tennata Apostolov, 1990 had to be excluded from the phylogenetic revision, due to imprecise and fragmentary description; its systematic position is pending until fur- ther material is available for re-examination and re-de- scription, so within the Laophontidae, it is regarded here as species incertae sedis. The remaining nine species are retained in Echinolaophonte, which is now characterised as a monophylum by means of one autapomorphy, i.e. the presence of a dorsal single spur on the posterior mar- gin of the cephalothorax. Moreover, with the description of E. musa sp. nov. from Jeju Island and the elevation of E. armiger f. briani Lang, 1965 to the species level (E. briani Lang, 1965), the number of species assigned to Echinolaophonte increases to 11. Together with findings of E. oshoroensis in Japan (It6 1969) and E. mirabilis Gurney, 1927 in China (Zhang and Li 1976), E. musa sp. nov. is the third representative of Echinolaophonte reported from Asian waters. The report of E. mirabilis from Jeju Island (Korea) by Kim (2013) is, however, erroneous. Re-exmination of that material revealed that it actually belongs to E. musa sp. nov. The here presented phylogenetic re-evaluation of Echinolaophonte elucidates its former ambiguous phy- logenetic status and, thus, might be a helpful step to- wards the solution of the phylogenetic unclarities within the Laophontidae. Acknowledgements The first author would like to express his gratitude to Dr Gritta Veit-Kohler, Senckenberg am Meer, Abt. DZMB, Wilhelmshaven, Germany, for her helpful advice and providing conveniences during his visit to the German Centre for Marine Biodiversity Research (DZMB) and he wishes to express his appreciation to Dr Karin Rich- ter, Untere Naturschutzbehérde, Emden, Germany, for her helpful support in Confocal Laser Scanning Micros- copy (CLSM) examination. The authors specially thank Dr Hyun Soo Rho, Korea Institute of Ocean Science and Technology, for collecting samples on Munseom Islet, Jeju Island. The authors are indebted to Dr Seher Kuru, Mersin University, Mersin, Turkey/Senckenberg am Meer, Abt. DZMB, Wilhelmshaven, Germany, for helpful and constructive hints and comments on a former draft of the manuscript. Similarly, three reviewers are thanked for very helpful and constructive comments on the man- uscript. This research was supported by the Discovery of Korean Indigenous Species Project, National Institute of Biological Resources. This is publication number 63 that uses data from the Senckenberg am Meer Confocal Laser scanning Microscope Facility (SGN-SaM-cLSM). This research was supported by “Development of Advanced Science and Technology for Marine Environmental Im- pact Assessment” of Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries (KIMST-20210427). Zoosyst. Evol. 99 (1) 2023, 217-252 References Apostolov A (1990) Quelques espéces de la famille Laophontidae T. Scott (Copépodes, Harpacticoides) de Monaco. Skopje, Macedonia: Fragmenta balcanica 14: 163-177. Ax P (1984) Das phylogenetische System. Gustav Fischer Verlag, Stuttgart, 349 pp. Ax P (1988) Systematik in der Biologie. Gustav Fischer Verlag, Stuttgart, 181 pp. Ax P (1995) Das System der Metazoa I. Gustav Fischer Verlag, Stuttgart, 226 pp. Baird W (1850) The natural history of the British Entomostraca. The Ray Society, London, 364 pp. https://doi.org/10.5962/bhl title.39641 Bodin P (1997) Catalogue of the new marine harpacticoid copepods (1997 edn). Documents de travail de |’ Institut royal des Sciences naturelles de Belgique 89: 1-304. Boxshall GA, Halsey SH (2004) An introduction to copepod diversity I. The Ray Society 166, London, 421 pp. Brady GS (1880) A monograph of the free and semi-parasitic Copepoda of the British Islands. II. The Ray Society, London, 182 pp. Brian A (1917) Descrizione di una nuove specie di Laophonte (L. quaterspinata n. sp. mihi) proveniente dai materiali del labora- torio marino di Quarto. Monitore Zoologico Italiano 28: 174-178. Brian A (1928) Descrizione di specie nuove o poco conosciute di co- pepodi bentonici del mare Egeo. Bollettino dei Muse di Zoologia e di Anatomia Comparata Genova 7: 1-37. Buchholz R (1874) 8. Crustaceen. In: Verein fiir die deutsche Nordpo- larfahrt in Bremen (Ed.) Die zweite deutsche Nordpolarfahrt in den Jahren 1869 und 1870 unter Leitung des Kapitaén Karl Koldewey. Band 2. Wissenschaftliche Ergebnisse, 262-398. Chislenko LL (1967) Copepoda Harpacticoida of the Karelia coast of the White Sea. Issledovaniia Fauny Morei: Akademiia nauk SSSR, Moscow 7: 48-196. Chislenko LL (1977) Harpacticids (Copepoda, Harpacticoidea) from sponges of Franz Josef Land. Issledovaniya Fauny Morei 14: 237-270. Claus C (1863) Die frei lebenden Copepoden mit besonderer Bertick- sichtigung der Fauna Deutschlands, der Nordsee und des Mittel- meeres. Wilhelm Engelmann Verlag, Leipzig, 230 pp. https://dot. org/10.5962/bh1.title.58676 Cottarelli V, Forniz C (1991) Laophontidae from the meiobenthos of some circumsardinian islets: Echinolaophonte armiger typica and Echinolaophonte minuta n. sp. (Crust., Copep., Harpact.). Annali del Museo Civico di Storia Naturale Giacomo Doria 88: 665-676. Cottarelli V, Forniz C, Bascherini S (1992) Benthic and interstitial La- ophontidae (Copepoda, Harpacticoida) from Ischia, Naples, Italy, with the description of Echinolaophonte veniliae n. sp. Crustaceana 62(3): 283-299. https://doi.org/10.1163/156854092X00172 de Paiva Carvalho J (1952) Sdbre uma colegao de Copepodos, nao parasiticos, da Baia de Santos e suas adjacéncies. Boletim do In- stituto Oceanografico 3(1-2): 152-165. https://doi.org/10.1590/ S0373-55241952000100012 Fiers F (1991) Allocation of Laophonte trispinosa Sewell to Xanthilaop- honte gen. nov. and the description of X. carcinicola spec. nov. (Harpac- ticoida: Laophontidae). Zodlogische Mededeelingen 65(22): 287-312. Fiers F (1992) A redescription of Hemilaophonte janinae Jakubisiak (Copepoda, Harpacticoida), a laophontid living in the gill chambers of the common spider crab. Belgian Journal of Zoology 122(2): 211-222: 251 Fuentes-Reinés JM, Suarez-Morales E (2017) A new species of 1927) (Crustacea, Copepoda, Harpacticoida, Laophontidae) from the Caribbean with a key to species. ZooKeys 722: 19-36. https://doi. org/10.3897/zookeys.722.14560 George KH (2020) Restructuring the Ancorabolidae Sars (Copepoda, Echinolaophonte and record of E. armiger (Gurney, Harpacticoida) and Cletodidae T. Scott, with a new phylogenet- ic hypothesis regarding the relationships of the Laophontoidea T. Scott, Ancorabolidae and Cletodidae. Zoosystematics and Evolution 96(2): 455-498. https://doi.org/10.3897/zse.96.51349 George KH (2021) Four new genera of the Ceratonotus group (Copep- oda, Harpacticoida), including the description of two new species. European Journal of Taxonomy 774: 1-41. https://doi.org/10.5852/ ejt.2021.774.1525 George KH, Lehmanski LMA, Kihara TC (2020) Revision of the genus Laophontodes T. Scott (Copepoda, Harpacticoida, Ancorabolidae), including the description of a new species and a key to species. ZooKeys 997: 17-46. https://doi.org/10.3897/zookeys.997.56965 Gomez S, Boyko CB (2006) Ona small collection of harpacticoids from Easter Island: the family Laophontidae T. Scott (Crustacea: Copep- oda: Harpacticoida). Zootaxa 1352: 3-70. Gurney R (1927) Zoological results of the Cambridge expedition to the Suez Canal, 1924. 23. Report on the Crustacea—Copepoda (littoral and semi-parasitic). Transactions of the Zoological Society of London 22: 451-577. https://doi.org/10.1111/j.1096-3642.1927.tb00207.x Hamond R (1973) Some Laophontidae (Crustacea: Copepoda: Har- pacticoida) from off North Carolina. Transactions of the American microscopic. Society 92(1): 44-59. https://doi.org/10.2307/3225170 Hennig W (1982) Phylogenetische Systematik. Paul Parey Verlag, Hamburg, 246 pp. Huys R (1990) A new family of harpacticoid copepods and an anal- ysis of the phylogenetic relationships within the Laophontoidea T. Scott. Biydragen tot de Dierkunde 60(2): 79-120. https://doi. org/10.1163/26660644-06002002 Huys R (2009) On the junior subjective synonyms of Cou/lia Hamond, 1973 (Copepoda, Harpacticoida, Laophontidae): An update and key to species and related genera. ZooKeys 5: 33-40. https://dot. org/10.3897/zookeys.5.64 Huys R, Boxshall GA (1991) Copepod Evolution. The Ray Society, London, 468 pp. https://doi.org/10.43 19/lo.1993.38.2.0478 Huys R, Lee W (1998/99) On the relationships of the Normanellidae and the recognition of Cletopsyllidae grad. nov. (Copepoda, Harpac- ticoida). Zoologischer Anzeiger 237: 267-290. Huys R, Willems KA (1989) Laophontopsis Sars and the taxonomic concept of the Normanellinae (Copepoda: Harpacticoida): a re- vision. Bijdragen tot de Dierkunde 59(4): 203-277. https://doi. org/10.1163/26660644-05904002 Huys R, Gee JM, Moore CG, Hamond R (1996) Marine and Brackish Water Harpacticoid Copepods. Part 1. Synopses of the British Fauna 51: 1-352. It6 T (1969) Descriptions and records of marine harpacticoid copepods from Hokkaido, II. Journal of the Faculty of Science, Hokkaido Uni- versity, Series VI. Zoology 17: 58-77. Jakubisiak S (1933) Sur les Harpacticoides hébergés par Maia squinado. Bulletin de la Société Zoologique de France 57: 506-513. Kim SH (2013) Invertebrate Fauna of Korea, Marine Harpacticoida II. National Institute of Biological Resources. Ministry of Environment 21(27): 1-105 zse.pensoft.net 252 Kornev PN, Chertoprud ES (2008) Harpacticoid copepods from the White Sea: Morphology, Systematics, Ecology. KMK Scientific Press, Moscow, 367 pp. [in Russian] Krishnaswamy S (1957) Studies on the Copepoda of Madras. PhD the- sis, Université Madras, India, 168 pp. Kuru S, Sénmez S, Karaytug S (2019) A new species of the genus 1941 Laophontidae) from the Aegean Sea coast of Turkey. Turkish Journal of Zoology 43(2): 171-184. https://doi.org/10.3906/zoo- 1809-20 Lang K (1948) Monographie der Harpacticiden, two volumes. Otto Echinolaophonte Nicholls, (Copepoda, Harpacticoida, Koeltz Science Publishers, Konigstein, 1682 pp. Lang K (1965) Copepoda Harpacticoida from the Californian Pacif- ic coast. Kungliga Svenska Vetenskapsakademiens Handlingar (4)10(2): 1-560. Lee W, Huys R (1999) Bathylaophonte gen. nov. from deep-sea hydro- thermal vents and the polyphyly of Paronychocamptus (Copepoda: Harpacticoida). Cahiers de Biologie Marine 40: 293-328. Lee W, Soh HY, Montagna PA (2006) Redescription of Echinolaophon- te armiger (Gumey) (Copepoda: Harpacticoida) from the Gulf of Mexico. Zootaxa 1250: 53-68. McCormack E (2006) Carraroenia ruthae gen. et sp. nov. (Copepoda, Harpacticoida, Laophontidae) from maerl substrates of the Irish west coast. Zootaxa 1202(1): 39-52. https://doi.org/10.11646/zoo- taxa.1202.1.4 Menzel L, George KH (2009) Description of four new species of Mesocletodes Sars, 1909 (Copepoda, Harpacticoida, Argestidae) and redescription of Mesocletodes robustus Por, 1965 from the South Atlantic, including remarks on the Mesocletodes abyssicola group. Zootaxa 2096(1): 214-256. https://doi.org/10.11646/zoot- axa.2096.1.14 Mielke W (1981) Interstitielle Fauna von Galapagos. XX VIII. Laophon- tinae (Laophontidae), Ancorabolidae (Harpacticoida). Mikrofauna Meeresboden 84: 1-106. Muller OF (1792) Entomostraca seu Insecta Testacea quae in aquis Daniae Et Norvegiae Reperit. JC Hermann, Francofvrti Ad Moenvm, 135 pp. Nicholls AG (1941) Littoral Copepoda from South Australia. I. Harpac- ticoida. Records of the South Australian Museum 6: 381-427. Nicholls AG (1945) Marine Copepoda from Western Australia. HI. Lit- toral harpacticoids from Port Denison. Journal and Proceedings of the Royal Society of Western Australia 29: 1-16. Noodt W (1958) Die Copepoda Harpacticoidea des Brandungsstrandes von Teneriffa (Kanarische Inseln). Abhandlungen der Mathema- Akademie der Wissen- schaften und der Literatur in Mainz 1958(2): 53-116. Norman MA (1876) Crustacea, Tunicata, Polyzoa, Echinodermata, tisch-Naturwissenschaftlichen Klasse. Actinozoa, Foraminifera, Polycistina and Spongida. In: Jeffreys JG (ed.). Preliminary Report of the Biological Results of a Cruise in H.MLS. ‘Valorous’ to Davis Strait in 1875. Proceedings of the Royal Society 25(1877): 202-215. zse.pensoft.net Song, S.J. et al.: Phylogenetic revision of Echinolaophonte Pesta O (1959) Harpacticoiden (Crust. Copepoda} aus submarinen Hohlen und den benachbarten Litoralbezirken am Kap von Sorrent (Neapel). Ergebnisse der Osterreichischen Tyrrhenia-Expedition 1952. Teil: VI., Pubblicazione della Stazione Zoologica di Napoli 30, Supplemento: 94-177. Por FD, Marcus A (1972) Copepoda Harpacticoida of the Suez Canal. In: Contributions to the knowledge of Suez Canal migration. Israel Journal of Zoology 21(3-4): 249-274. Sars GO (1908) Copepoda Harpacticoida. Parts XXI & XXII. Laop- hontidae (Continued). An account of the Crustacea of Norway, with short descriptions and figures of all the species 5: 241-256. Sars GO (1921) Copepoda Supplement. Parts IX & X. Harpacticoida (concluded), Cyclopoida. An account of the Crustacea of Norway, with short descriptions and figures of all the species 7: 93-121. Schminke HK (1976) The ubiquitous telson and the deceptive furca. Crus- taceana 30(3): 292-299. https://doi.org/10.1163/156854076X00657 Seifried S (2003) Phylogeny of Harpacticoida (Copepoda): Revision of “Maxillipedasphalea’ and Exanechentera. Cuvillier Verlag, Gottin- gen, 259 pp. Ummerkutty ANP (1970) Studies on Indian copepods 10. Description of Parapeltidium nichollsi sp. n., Porcellidium unicus sp. n. and Echinolaophonte tropica sp. n. obtained from the southeast coast of India. Records of the Zoological Survey of India 64(1—4): 155-162. https://doi.org/10.265 15/rzsi/v64/11-4/1966/161534 van Douwe C (1929) 4. Marine Litoral-Copepoden: Zur Verbreitung des Genus Laophonte Philippi im Mittelmeer. Zoologischer Anzeiger 83(11/12): 283-294. Vervoort W (1964) Free-living Copepoda from Ifaluk Atoll in the Caroline Islands with notes on related species. Bulletin — United States National Museum 236(236): 1-431. https://doi.org/10.5479/ s1.03629236.236.1 Walter TC, Boxshall GA (2022) World of Copepods Database. Echi- nolaophonte Nicholls, 1941. Accessed through: World Register of Marine Species. https://www.marinespecies.org/aphia.php? p=tax- details&id=115367 [on 2022-03-23] Wells JBJ (2007) An annotated checklist and keys to the species of Copepoda Harpacticoida (Crustacea). Zootaxa 1568(1): 1-872. https://doi.org/10.11646/zootaxa. 1568.1.1 Wells JBJ, Rao GC (1987) Littoral Harpacticoida (Crustacea: Copepo- da) from Andaman and Nicobar Islands. Memoirs of the Zoological Survey of India 16(4): 1-385. Willen E (1992) Nachbeschreibung von Heterolaophonte minuta (Boeck, 1872) (Copepoda, Harpacticoida) und Bemerkungen zur systematischen Stellung sowie zur Biologie der Art. Drosera 92(2): 139-153. [in German] Willey A (1930) Harpacticoid Copepoda from Bermuda. Part I. Annals & Magazine of Natural History 6(10): 81-114. https://dot. org/10.1080/00222933008673 192 Zhang C, Li Z (1976) Harpacticoida (Copepoda, Crustacea) from Xisha Islands of Guangdong Province, China. Acta Zoologica Sinica 22(1): 66-70.