GECKO CLASSIFICATION 



15 



Diplodactylyus, as recognised by Underwood, corresponds to two 

 currently recognised genera, Diplodactylus and Strophurus. His 

 reconstituted Phyllodactylus included forms now placed in that 

 genus as well as Asaccus, Afrogecko, Euleptes, Christinus, 

 Crenadactylus, Paroedura and Urocotyledon (based on his list of 

 specimens examined). He also separated Narudasia from 

 Quedenfeldtia, and divided the then cosmopolitan Gymnodactylus 

 into four genera: Gymnodactylus (restricted to South America), 

 Phyllurus (corresponding to the current Phyllurus and Saltuarius, 

 but also including the species vankampeni, now allocated to the 

 gekkonine genus Nadus), Cyrtodactylus (including representatives 

 of Cyrtodactylus, Geckoella, Tenuidactylus. Mediodactylus, Nactus), 

 and Wallsaurus (the latter now synonymized with Homonota, a 

 genus listed as unexamined by Underwood). 



STEPS TOWARDS FURTHER SYSTEMATIC 

 RESOLUTION 



Underwood's ( 1 954) classification provided a springboard for sub- 

 sequent systematic work on geckos. The four large units he 

 established were 'corrected' by Kluge (1967a), but remained as the 

 chief elements in Kluge's higher order treatment of the group. 

 Moffat (1973) generally accepted Kluge's (1967a) allocation of 

 genera to subfamilies but disagreed with his methodology and his 

 pattern of subfamilial relationships. 



Eublepharidae 



The most stable unit has been the Eublepharidae. This group was 

 retained intact by Kluge (1967a), although reduced to subfamilial 

 rank. All subsequent researchers have accepted the monophyly of 

 this group and more recent treatments have reflected the phylogenetic 

 position of the Eublepharidae as the sister-group of all other gekkotans 

 by again according it familial rank (e.g. Grismer 1988). Further, 

 patterns of relationship within the eublepharids have been estab- 

 lished at the generic and species levels (Grismer, 1988, 1991, 1994; 

 Grismer et al. 1999; Olaet al.. 1999). In this instance. Underwood 

 (1954) chiefly used primitive features in diagnosing the family (e.g. 

 true eyelids present, etc.) but subsequent research has identified 

 numerous synapomorphies that support the reality of this mono- 

 phyletic unit (Grismer, 1988; Ota et ai, 1999). 



Sphaerodactylidae 



The Sphaerodactylidae of Underwood has remained unchanged in 

 terms of generic content. Kluge (1967a) recognised the group as a 

 subfamily and considered it to be highly derived, in contrast to 

 Underwood ( 1 954), who interpreted it as a primitively diurnal group 

 and a relatively early offshoot of the gekkotan lineage. Subsequently 

 Kluge (1987) demonstrated that sphaerodactyls are derived from 

 within gekkonines, confirming their monophyly while obviating 

 their recognition as a higher order group, as such recognition would 

 render the Gekkoninae paraphyletic. This arrangement also re- 

 ceived support from reproductive characters including the restriction 

 of the calcareous eggshell to gekkonines and sphaerodactylines 

 (Bustard 1968; Werner 1972). Kluge (1995) later conducted an 

 explicit investigation of the phylogeny of the sphaerodactyls, yield- 

 ing a fully resolved generic level pattern for the group. Kluge ( 1 995) 

 regarded the gekkonine Pristurus as the immediate sister group of 

 the sphaerodactyls and considered Quedenfeldtia, Cnemaspis, 

 Narudasia and Saurodactylus as other appropriate outgroup taxa for 

 his analysis (see below). Of these outgroup genera, Underwood 



examined material of only Narudasia and Saurodactylus. Species 

 level analyses within individual sphaerodactyl genera are ongoing 

 and have been attempted for the largest genus, Sphaerodactylus 

 (Hass 1991, 1996). 



Diplodactylinae 



The composition of the Diplodactylinae has changed most signifi- 

 cantly. Kluge (1967a, b) removed a large number of genera from this 

 group to the Gekkoninae, leaving only forms with parchment- 

 shelled eggs in his Diplodactylinae, and provided a generic level 

 hypothesis of relationships among the remaining forms. Bauer 

 (1990a) erected a species level hypothesis of relationships among 

 the Carphodactylini, one of two tribal groups established by Kluge 

 (1967a). Additional hypotheses at the species level have been 

 presented by Good et al. (1997) and Vences et al. (2001). The 

 Diplodactylini, also established by Kluge (1967a), has yet to be 

 investigated phylogenetically at the species level, although Kluge 

 ( 1967b) erected a generic level hypothesis of relationships and King 

 ( 1 987b) suggested a species level phylogeny of Diplodactylus based 

 on several karyotypic characters. Underwood (1954) had purged the 

 genus Diplodactylus of two taxa with Gekko-type pupils, rendering 

 a cluster of taxa still accepted as monophyletic. However, he re- 

 tained in Phyllodactylus the species ocellatus, which has since been 

 recognised as a diplodacty line and placed in the genus Crenadactylus. 



Although the content of Underwood's (1954) Diplodactylinae as 

 a whole has changed little, argument persists over patterns of 

 internal relationship. In particular, the monophyly of the 

 Carphodactylini has been called into question (Donnellan et al. 

 1999) and the relationship of New Zealand taxa has also been re- 

 evaluated (Chambers et al. 2001). King (1987b) and King and 

 Mengden ( 1990), based on chromosomal data, argued that Oedura 

 was more closely allied to the Carphodactylini than to other 

 Diplodactylini. and that pygopods are also allied to the 

 carphodactylines. Donnellan et al. ( 1999), based on molecular data 

 ( 12SRNA, c-mos), regarded the Diplodactylini , including Oedura. 

 as monophyletic, but suggested that the Carphodactylini is 

 paraphyletic. They found pygopods to be the sister group of all 

 Diplodactylines. 



Patterns of relationship within the Diplodactylinae have further 

 been complicated by the recognition that pygopods are more closely 

 related to this group (or some component thereof) than to other 

 gekkotans (Kluge 1987). On this basis, Kluge (1987) recognised a 

 redefined Pygopodidae for the group that includes diplodactyline 

 geckos plus pygopods. Good et al. (1997), based in part on argu- 

 ments presented by Bauer (1990a), proposed an alternative higher 

 level scheme, recognising the Diplodactylidae as a family level 

 group. Based on the patterns of relationship retrieved by Donnellan 

 et al. ( 1999), the Diplodactylidae and Pygopodidae are sister taxa. 



As mentioned above, the genus Eurydactylodes proved particu- 

 larly problematic to Underwood ( 1 954) and he only included it in his 

 Diplodactylinae in the following year (Underwood, 1955). For a 

 variety of reasons, this genus has continued to be enigmatic, exhib- 

 iting an odd mosaic of characteristics. Although Eurydactylodes 

 appears to be a member of a monophyletic New Caledonian 

 carphodactyline radiation (Bauer 1990a), it possesses a number of 

 features that are problematic and, at least superficially, link it to 

 other groups of geckos. One such feature is the tail-squirting appa- 

 ratus. Members of this genus have caudal glands that secrete a sticky 

 substance as a defensive mechanism. Such mechanisms have been 

 widely reported in arthropods (Deslippe et al. 1996), and amphi- 

 bians (Arnold 1982), but among amniotes have been noted only for 

 geckos of the Australian diplodactyline genus Strophurus (Rosenberg 



