Beu: Evolution of Janthina and Recluzia 
173 
Janthina krejcii sp. nov. 
Figs 26A-N 
Hartungia typica Bronn.-Bronn, 1862: 32-33 (in part 
misidentified as H. typica Bronn, 1861). 
Janthina typica (Bronn).-Krejci-Graf et ah, 1958: 336, pi. 
3, fig. 6, pi. 4, fig. 11 (misidentification). 
Type material. Holotype SMF10135a (Figs 26A-B, D-E), 
with two paratypes SMF10135b-c (Figs 26C, F-H), labelled 
“Azoren, Santa Maria, Wegknick [road bend] bei Praia, 
K. Krejci-Graf,” 23 April 1955, in SMF. The type locality 
is the upper, seaward-directed hairpin bend on the road 
descending from Almagreira to the beach at Praia, Santa 
Maria Island, illustrated by Krejci-Graf et al. (1958: fig. 4) 
(a lower, landward-directed hairpin bend is in the underlying 
volcanic rocks). The writer visited the pale grey outcrop 
labelled “ Janthina find-point alongside the collectors” in 
fig. 4 of Krejci-Graf et al. (1958) with Bernard Landau on 
28 Feb 1998, but found no calcareous fossils. The matrix 
proved non-calcareous, and is not datable by microfossils; it 
lacks Foraminifera, Radiolaria, calcareous nannofossils and 
dinoflagellate cysts. Evidently Krejci-Graf s party sampled 
a last small pocket of calcareous rock, probably between 
volcanic blocks at the base of the outcrop. However, a new 
lookout, the Miradouro de Macela, was being constructed 
during Feb 1998 to overlook the beach at Praia, at the 
seaward extremity of the bend, across the road and behind 
the photographer in Krejci-Graf et ah's (1958: fig. 4) 
photograph. The soft, fawn, non-calcareous, tuffaceous 
sandstone in the foundations of the lookout was found to 
contain numerous moulds of Janthina krejcii sp. nov. Ten 
of these are here designated as paratypes (GNS WM18973; 
the two most complete illustrated, Figs 26I-N), and three 
others are incomplete. Colom (in Krejci-Graf e/ ah, 1958: pis 
5-6) illustrated planktonic foraminiferans in a sample from 
quarries near Figueiral on the south side of Pico do Facho, 
near the Miradouro de Macela, including Globoconella 
puncticulata (Deshayes, 1832), Hirsutella cf. margaritae 
(Bolli & Bermudez, 1965) and Globigerinoides sacculifer 
(Brady, 1877) (reidentified by M. Crundwell, GNS, pers. 
comm. 17 Sep 2012), a diagnostic Zanclean fauna. The 
age of the type locality of Janthina krejcii has not been 
determined in detail but, as it is at a similar elevation to the 
quarries sampled by Krejci-Graf et ah (1958) and the Cre 
locality described by Janssen et ah. (2008), is likely to be 
a similar age within Zanclean time. Only the type material 
has been observed. 
Distribution. The writer has seen specimens of Janthina 
krejcii sp. nov. only from the type locality and the outcrop 
across the road from it, at the lookout (Miradouro de Macela) 
on the road descending from Almagreira to Praia, Santa 
Maria Island, Azores Islands. Bronn (in Reiss, 1862: 33) 
noted that one of his specimens of Janthina typica from near 
Praia was crushed but lacked spiral folds, so his material 
seems to have included a specimen of J. krejcii sp. nov. from 
the type locality. He discussed whether it might be a distinct 
species, but concluded this was individual variation. As with 
all other relevant early collections, the present location of 
Reiss’s material is not known to the writer. Mayer (1864: 
93, 101) also recorded a single specimen of “ Janthina 
hartnngi ” from Praia, but as it is not mentioned in the list 
of material following his description (Mayer, 1864: 63), 
he presumably merely repeated Bronn’s record. However, 
Mayer (1864: 63) also recorded a specimen of Janthina 
hartungi ” without spiral folds from Pinheiros, a locality a 
short distance northeast of Cre, Santa Maria Island. As the 
writer has not seen material from Pinheiros, it is possible 
that J. krejcii sp. nov. occurs more widely on Santa Maria 
Island than the present record indicates. 
Dimensions. See Table 4. Most paratype moulds are 
too incomplete or too distorted to measure. The largest 
fragmentary paratype in WM18973 is 34 mm wide, but is 
compressed significantly; a maximum diameter of c. 32 
mm is likely. 
Diagnosis. Teleoconch moderately large, short and wide 
(D/H 1.2-1.35), spire very low to almost flat, whorls evenly 
convex; completely covered with fine, straight, acline axial 
ridges, but without obvious spiral sculpture. Outer lip 
straight, acline; sinus small, moderately deep, semicircular 
to weakly V-shaped, situated at base of lip. 
Description. Teleoconch moderate-sized for genus, reaching 
c. 32 mm in diameter and 25 mm in height, wide (D/H 
1.2-1.35), very low-spired, with c. 3.5 evenly and strongly 
convex teleoconch whorls; without obvious spiral sculpture. 
Spire little elevated above last whorl; suture appressed. Axial 
sculpture of many closely spaced, straight, thin, acline, low 
lamellae with flat-bottomed interspaces, extending from 
suture to umbilical hollow over entire teleoconch, c. 1 mm 
apart at periphery on last whorl. Aperture large, tall, almost 
vertical, with thin lips; columellar area and umbilical hollow 
poorly preserved in all material, apparently similar to those 
of Janthina typica and J. chavani. Outer lip sinus against 
base of columella, moderately large, semicircular to weakly 
V-shaped as in J. chavani , visible in only two paratype 
moulds in WM18973. Protoconch not seen. 
Remarks. Janthina krejcii sp. nov. resembles J. typica 
and J. chavani in its uniform sculpture of fine, closely 
spaced, straight axial ridges over the entire teleoconch 
and in its semicircular to shallowly V-shaped outer-lip 
sinus situated at the base of the lip. However, it differs 
from them both in its consistently very low to almost flat 
spire, so that width is significantly greater than height in 
all specimens, and in its complete lack of obvious spiral 
sculpture. It also reaches a markedly smaller maximum 
diameter than J. chavani, although similar in width to J. 
typica. Were only K. Krejci-Graf’s original specimens 
available they might be thought aberrant specimens of J. 
typica, but all 10 reasonably complete moulds and several 
additional fragments from the Miradouro de Macela (GNS 
WM18973) are consistent with Krejci-Graf s specimens in 
their low spire and in completely lacking spiral folds. With 
15 consistent specimens available, it must be concluded 
that this is a previously unrecognized species of Janthina. 
Table 4. Dimensions of Janthina krejcii sp. nov. 
locality 
height 
diameter 
D/H 
H/D 
holotype SMF 10135a 
23.0 
30.8 
1.34 
0.75 
paratype SMF10135b 
20.7 
27.0 
1.30 
0.77 
paratype SMF 10135c 
16.8 
22.6 
1.35 
0.74 
paratype GNS WM18973 
22.6 
26.8 
1.19 
0.84 
paratype GNS WM18973* 
24.4 
23.8 
0.98 
1.03 
paratype GNS WM18973 
21.4 
25.2 
1.18 
0.85 
* Distorted. 
