Homoplasy in shells discombobulated the taxonomy: revision of the larger helicarionid land snails of northern Queensland, Australia (Stylommatophora: Helicarionidae)
Author
Hyman, Isabel T.
Author
Köhler, Frank
text
Journal of Natural History
2022
2022-11-23
56
41 - 44
1727
1799
http://dx.doi.org/10.1080/00222933.2022.2136017
journal article
198290
10.1080/00222933.2022.2136017
c9288626-198f-4b45-b923-f134cc0df48a
1464-5262
7380681
83362BEC-6E6B-4B65-AC1E-F49762C744B8
Pravonitor septentrionalis
sp. nov.
(
Figures 4
,
14
(h), 20)
Etymology
From
septentrionalis
(Latin = northern), referring to the species’ range at the northernmost tip of Cape
York
peninsula.
Material examined
Holotype
.
QM
MO86001
. c. 4.0 km N of
Lockerbie
,
Cape York Development Rd
,
Far North Qld
,
Australia
; coll.
22 September 1988
;
J. Stanisic
,
D. Potter
,
J. Chaseling.
Paratypes
.
QM
MO21832
,
MO15621
,
MO21629
.
Diagnosis
External morphology.
Shell (
Figure 14
(h)) small (SW
7.7–9.3 mm
), pale golden amber, 4.9–5.5 whorls, subdiscoidal to subglobose with a moderately raised spire, whorl profile rounded, sutures impressed; microsculpture of very fine spirals on protoconch and teleoconch, becoming obsolete on later whorls; umbilicus very narrow, lip reflected over opening, thickened columella with small notch. Body white (in alcohol). Right and median mantle lobes moderately small, left lobe small; shell lappets moderately long, narrow, tapering, left slightly shorter than right. Caudal horn moderately large.
Figure 20.
Genitalia of
Pravonitor septentrionalis
. a-c) QM MO86001 (holotype), Lockerbie. a) Reproductive system. b) Penis interior. c) Penial complex. d) QM MO15621 (paratype), Bamaga. Spermatophore. Scale bars: 1 mm.
Genital anatomy.
Genitalia (
Figure 20
) with very short to absent vagina; bursa copulatrix moderately long, duct slightly broader at base, sculptured internally with longitudinal ridges; bursa elongate. Penis long, bulging at base, tubular medially; internally with one pustulose longitudinal pilaster basally, internal wall sculptured with fine pustules; basal bulge with thickened folds; base not enclosed in penial tunica; tunica enclosing approx. 50–60% of penis. Epiphallus enters penis through a small verge; epiphallus shorter than penis; epiphallus 2 slightly longer than epiphallus 1; moderately short epiphallic caecum present, with medial attachment of the penial retractor muscle; flagellum long, slender, with L-shaped tip; very small internal cryptae visible. Spermatophore with soft capsule and elongate tail-pipe sculptured with small hook-like spines.
Remarks
Pravonitor septentrionalis
sp. nov.
, initially designated as
Pravonitor kreffti
‘Cape
York’, is known only from a small area on the tip of Cape
York
peninsula, from just south of Bamaga to Punsand Bay. It is probably sympatric with
P. kreffti
near Punsand Bay, and in the past has been identified as this species, but comparison with the
type
images and early descriptions has shown that
P. kreffti
is significantly larger.
Pravonitor septentrionalis
also bears a close resemblance to
Geminitor wenlockensis
, which is found farther to the south between Weipa and the Portlands Rd crossing of Wenlock River. However,
G. wenlockensis
has a glossier shell surface, a sealed umbilicus partially covered by a reflected lip, and a weaker columellar thickening.