New species of Neritidae (Neritimorpha) from the Ypresian and Bartonian of the Paris and Basse-Loire Basins, France
Author
Symonds, Malcolm Francis
Author
Pacaud, Jean-Michel
text
Zootaxa
2010
2606
55
68
journal article
47583
10.5281/zenodo.197721
7fbbbf17-731f-4905-a25b-cea2c544bf38
1175-5326
197721
Clithon (Pictoneritina) barbei
sp. nov.
(
Fig. 3
a–c)
Type
material.
Holotype
NHM PI TG 26448 (M. Symonds coll.,
Fig. 3
a–c). One
paratype
NHM PI TG 26449 (M. Symonds coll.), one
paratype
MNHN
A33473
(Ledon coll.). All from
type
locality.
Stratum typicum.
Early Eocene, Ypresian (Sparnacian), “Sands of Pourcy”.
Locus typicus.
Pourcy, Marne,
France
. 49˚09ˏ43˝ N 3˚54ˏ21˝ E.
Derivatio nominis.
Named after Gérard Barbe of Champillon, Marne,
France
, a palaeontologist, who is familiar with the fossils of Pourcy, and who assisted the senior author with the collection of material from there, in which the
types
of this taxon were found.
Diagnosis.
A small semiglobose
Pictoneritina
; spire depressed, septum with poorly defined teeth, colour pattern of three dark spiral bands on light background.
Description.
Shell small for subgenus, consisting of about 2.25 whorls, semiglobose with spire depressed. Protoconch small, approximately
0.2 mm
wide, smooth, almost spherical. Teleoconch about 2.25 whorls, evenly convex, increasing rapidly in size; surface glossy, smooth. Suture sharp, well defined. Colour pattern of 3 dark spiral bands on light background, highest immediately below suture, varying in width but usually narrower than spaces between them. Aperture oblique, semicircular. Septum convex, smooth. Septum edge slightly concave in centre; teeth consist of one rather broad, rounded, indistinct tooth at about one third of distance from adapical end of septum, 1 to 3 denticulations abapical to it, also indistinct. Outer lip evenly rounded, thin, smooth within. Apertural tooth low, curved ridge below abapical end of septum.
Size.
Holotype
: height
3.2 mm
, width
3.2 mm
.
Remarks.
Clithon
(
P.
)
barbei
is similar in size and shape to
Clithon
(
P.
)
nucleus
Deshayes, 1825
from the Cuisian of Cuise-la-Motte, Oise,
France
, although in that species the spire is usually wholly or partially covered by the following whorl. The colour pattern in
C.
(
P.
)
nucleus
consists of dark, wavy, transverse lines on a light background, in some specimens the transverse lines are interrupted by two or three pale spiral bands, while
C.
(
P.
)
barbei
has a colour pattern of 3 dark spiral bands on a light background.
Range and distribution.
Only known from
type
locality.