Muricopsis neraudeaui Merle, Pacaud, Ledon & Goret, 2024, n. sp.
Creators: name: Merle, Didier
name: Pacaud, Jean-Michel
name: Ledon, Daniel
name: Goret, Bernard
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Muricidae
Muricopsis
Muricopsis neraudeaui

description: Muricopsis neraudeaui n. sp.
(Figs 3 E-H; 25C, D)
urn:lsid:zoobank.org:act: 3804E413-7336-4510-ADC1-B1108F47EDA6
TYPE MATERIAL. — Holotype. France • Rennes Basin, Ille-et-Vilaine, Saint-Jacques-de-la-Lande; Yellow bed of the quarry; Late Miocene (lower Messinian); MNHN.F.A77746 (Néraudeau’s sample), H: 8.5 mm (Figs 3E, F; 25C).
Paratypes. France • 1 spm; same as for the holotype; MNHN.F.A77747 (Néraudeau sample, Figs 3G, H; 25D) • 12 spm; idem; MNHN.F.A90516 (Néraudeau’s sample).
ETYMOLOGY. — Dedicated to Didier Néraudeau who collected and provided the material.
TYPE HORIZON. — Yellow bed of the quarry, Late Miocene (lower Messinian), see Néraudeau et al. (2002).
TYPE LOCALITY. — France, Rennes Basin, Ille-et-Vilaine, Saint-Jacques-de-la-Lande (Lilion sand pit).
DISTRIBUTION. — Only known from the type locality.
DESCRIPTION
Protoconch not preserved. Teleoconch up to 8.5 mm in height, up to 4 mm in width, biconic in profile, composed of five whorls. Moderately high spire with subcarinate whorls. Last whorl up to 69.6% of total length. Apical angle 50°. Spiral sculpture with coarse primary cords. First whorl eroded; second whorl appearance of IP; P2 more developed than P1; second to fourth whorl: no change (IP, P1 and P2). Fifth whorl (last whorl): IP, P1 to P5, P6 atrophied (on siphonal canal), ADP and MP well developed, ABP poorly developed. Secondary cords s2 and s3. On second whorl: 12-13 varices; on fourth whorl: 10-11; on fifth whorl: 9-10 varices. On spire, axial ornamentation forming marked nodules on IP, P1 and P2. P1 and P2 nodules more developed than IP nodule. On convex part of last whorl, P1 to P5 acute nodules more or less equally developed; on siphonal canal, only ADP and MP displaying nodules. Ovate aperture up to 44% of diameter and up to 72% of length of last whorl (including siphonal canal). Columellar lip narrow, entirely adherent, bearing two tubercles anteriorly. No anal sulcus; no parietal callus. Outer lip with strong internal denticles. Series of denticles including ID, D2 to D5. D1 missing. D2 stronger. Outer lip not crenulate. Siphonal canal open, up to 32% of apertural length, slightly dorsally recurved. Pseudo-umbilicus narrow.
COMPARISONS
Like Muricopsis pontileviensis n. sp., M. neraudeaui n. sp. is another very small species for the genus and is comparable to the Langhian M. pontileviensis n. sp. in size. However, M. neraudeaui n. sp. is even smaller (8.5 mm for 5 whorls instead 12-14 mm for 5.5-6 whorls). Muricopsis neraudeaui n. sp. displays a stronger sculpture formed by acute nodules on IP, P1 to P5 and ADP, MP), whereas M. pontileviensis n. sp. bears only a swelling on the varices. In addition, the secondary cords are less numerous in M. neraudeaui n. sp. (only s2 and s3 instead s1, s2, s3, s4, s5 and s 6 in M. pontileviensis n. sp.). In spite of its very small size, M. neraudeaui n. sp. bears strong columellar denticles. This is the first record of very small Muricopsis species in fossil record. Assemblages containing very small species of Muricopsis are only documented in the Recent faunas. The best examples come from the islands of São Tomé and Martinique which contain several very small Muricopsis species (Houart 1996; Garrigues & Lamy 2019 respectively).
description: Published as part of Merle, Didier, Pacaud, Jean-Michel, Ledon, Daniel & Goret, Bernard, 2024, New Cenozoic Muricidae (Mollusca: Gastropoda) from Europe, pp. 495-551 in Geodiversitas 46 (15) on page 504, DOI: 10.5252/geodiversitas2024v46a15, http://zenodo.org/record/13985760