New Cenozoic Muricidae (Mollusca: Gastropoda) from Europe
Author
Merle, Didier
Author
Pacaud, Jean-Michel
Author
Ledon, Daniel
Muséum national d’histoire naturelle, Département Origines et Évolution (CR 2 P - MNHN, CNRS, UPMC, Sorbonne Université), 57 rue Cuvier, 75231 Paris cedex 05 (France) didier. merle @ mnhn. fr (corresponding author) jean-michel. pacaud @ mnhn. fr dnledon @ yahoo. fr
didier.merle@mnhn.fr
Author
Goret, Bernard
Raoul Ponchon, F- 31500 Toulouse (France) bernardgoret @ hotmail. com
bernardgoret@hotmail.com
text
Geodiversitas
2024
2024-10-24
46
15
495
551
https://sciencepress.mnhn.fr/sites/default/files/articles/pdf/g2024v46a15.pdf
journal article
304811
10.5252/geodiversitas2024v46a15
fe16163e-5e9d-4c80-89c8-fce3fb2e064f
1638-9395
13985760
urn:lsid:zoobank.org:pub:C32EAAFD-85D8-45CD-8DF7-B894E1537713
Timbellus occidentalis
n. sp.
(
Figs 8
A-C; 26A, B)
urn:lsid:zoobank.org:act:
53A32E50-A05D-4A09-B8B1-6CA776FDC29F
Murex
(
Pterymurex
)
tripteroides
–
Cossmann & Pissarro 1901: 78
, pl. 13, fig. 29 [
non
Lamarck, 1822
].
Timbellus
cf.
tripteroides
–
Merle
et al.
2011: 446
, pl. 101, figs 1, 2.
TYPE
MATERIAL
. —
Holotype
.
France
•
Normandy
,
Manche
,
Fresville
;
Calcaire
de Fresville
; middle
Eocene
(uppermost
Lutetian
);
MNHN
.F.A90533 (ex A24100 ex galerie de zoologie coll.,
Le Marchand
coll.), H:
20 mm
(
Figs 8A, B
;
26A
).
Paratypes
.
France
• 1 spm; same as for the holotype;
MNHN
.F.A90534 (ex A24100 ex galerie de zoologie coll., Le Marchand coll.)
• 4 spm; idem;
MNHN
.F.B63570 (de Morgan coll.)
• 1 spm,
MNHN
.F.A90532 (de Morgan coll.)
• 1 spm;
Normandy
, Manche, Hautteville-Bocage; middle Eocene (upper Lutetian);
MNHN
.F.A90531 (ex B63609, de Morgan coll.)
• 1 spm; idem;
MNHN
.F.B63609 (de Morgan coll.)
• 35 spm; idem;
MNHN
.F.B63610 (de Morgan coll.) – Gourbesville, Manche, middle Eocene (upper Lutetian)
• 3 spm; idem;
MNHN
.F.A24128 (Munier-Chalmas coll.)
• 10 spm;
Loire
Basin, Loire-Atlantique, Saffré (Bois-Gouët); middle Eocene (lower Bartonian);
MNHN
.F.A29658 (Pacaud coll.)
• 1 spm; idem;
MNHN
.F.A24031 (Vasseur coll.), figured in
Merle
et al.
(2011
: pl. 101, fig 1) as
Timbellus
cf.
tripteroides
(
Lamarck, 1822
)
(
Figs 8C
;
26B
) •
1 spm; idem;
MNHN
.F.J06383 (Vasseur coll.), figured in
Merle
et al.
(2011
: pl. 101, fig 2) as
Timbellus
cf.
tripteroides
(
Lamarck, 1822
)
.
ETYMOLOGY
. — From the Latin
occidentalis
meaning west, considering the geographic range of this species in
Normandy
and in the
Loire
Basin.
TYPE
HORIZON
. — Calcaire de Fresville, middle Eocene (uppermost Lutetian), see
Bignot
et al.
1968
).
TYPE
LOCALITY
. —
France
,
Normandy
, Manche, Fresville, see
APGN (2024)
.
DISTRIBUTION
. —
Normandy
(Calcaire de Fresville and Faluns de Hautteville) middle Eocene (uppermost Lutetian) and
Loire
Basin (Sables du Bois-Gouët), lowermost Bartonian see
Mathelin & Bignot (1989)
.
DESCRIPTION
Smooth, bulbous protoconch of 1.25 whorls. Teleoconch up to
26.6 mm
in height, up to
15.3 mm
in width, biconic in profile, composed of five whorls. Moderately high spire. Last whorl up to 85% total length. Apical angle 64° excluding spines, 91° including spines. Spiral sculpture with weak primary cords in adult specimens. First to fourth whorl, no cord. Fifth whorl: P1 to P3. Sixth whorl: P1 to P6 weak, s2 and no other cord below, ADP and MP occasional. On first whorl, eight protovarices. From second to last whorl, three varices and one intervarix intercalated Higher relief of intervarices on P2-P3. Varices lamellose, winged on last whorls. Appearance of short, straight P1 spine on third whorl. Sinus of P1 spine narrow and pointing adapically. On last whorl alate varices. Ovate aperture up to 9% of diameter and up to 80% of length of last whorl (including siphonal canal). Columellar lip smooth, narrow, slightly erect anteriorly, forming curved inductura at base. Parietal lip slightly adherent. Outer lip with denticles ID (occasional), D1 to D6, D1 and D2 more strongly developed. Outer lip not crenulate. Siphonal canal narrow, open, up to 49% of apertural length. Pseudo-umbilicus narrow.
4
3
cm
in
Width 2
1
0 0 1 2 3 4 5 6 7
Total length in cm
FIG
. 9. — Bivariate plot of total length against width comparing
Timbellus tripteroides
(
Lamarck,1822
)
from the middle Lutetian of Paris Basin (65 complete specimens) and
T. occidentalis
n. sp.
from the upper Lutetian of Normandy (18 complete specimens).
COMPARISONS
This species was previously attributed to
Murex tripteroides
Lamarck, 1822
by
Cossmann & Pissarro (1901)
and later with some doubts by
Merle
et al.
(2011)
. According to those authors, there are apparently strong similarities with
T. tripteroides
such as: a bulbous protoconch, an elongate shape, developed internal denticles, and few and weak cords. However,
T. occidentalis
n. sp.
is smaller and does not exceed
26 mm
for five teleoconch whorls. At the same size and same number of whorls
T. tripteroides
is still juvenile, does not bear internal denticles, and their axial wings are only developed on the last whorl (
Fig. 8D, E
). Adults of
T. tripteroides
can reach more than
60 mm
height at 7-8 whorls. A bivariate diagram (
Fig. 9
) illustrates the differences in size between
T. occidentalis
n. sp.
from
Normandy
and
T. tripteroides
from the Paris Basin. In addition, the spiral cords of
T. tripteroides
(
Figs 6
;
8D, E
) are usually more marked than those of
T. occidentalis
n. sp.
(
Fig. 8
A-C) Finally,
T. occidentalis
n. sp.
could be regarded as a progenetic species of
Timbellus
, because it associates a small size with adult characters comparable to
T. tripteroides
. Moreover, the two species never co-occur.
Timbellus occidentalis
n. sp.
ranges between the uppermost Lutetian (
Normandy
) and the lowermost the Bartonian (Loire-Atlantique), whereas
T. tripteroides
ranges from the lower to the middle Lutetian in the Paris Basin and in the
Hampshire
Basin during the Bartonian.