Timbellus longicanalis 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
Timbellus
Timbellus longicanalis

description: Timbellus longicanalis n. sp.
(Figs 11 A-D; 26E, F)
urn:lsid:zoobank.org:act: 59D8D20D-41AD-43F9-8A3B-B247A150B335
Timbellus fusoides – Merle et al. 2011: 446, pl. 101 fig. 5a, b only [non Deshayes, 1865].
TYPE MATERIAL. — Holotype. France • Normandy, Manche, Fresville; Calcaire de Fresville; middle Eocene (uppermost Lutetian); MNHN.F.A24101 (Le Marchand coll.), H: 35 mm (Figs 11A, B; 26E). Paratype. France • 1 spm; same as for the holotype; MNHN.F.A24100 (Le Marchand coll.) (Figs 11C, D; 26F).
ETYMOLOGY. — From the Latin adjective longus meaning elongated and canalis meaning canal, refecting the elongated siphonal canal of this species.
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); middle Eocene (uppermost Lutetian).
DESCRIPTION Protoconch not preserved. Teleoconch up to 35 mm in height, up to 14 mm in width, fusiform in profile, composed of six whorls. Moderately high spire. Last whorl up to 77% of total length. Apical angle 41° excluding spine and 61° including spines. Spiral sculpture with moderately marked primary cords on varices. First and second whorl eroded. Third whorl: appearance of weak s1 and P2 on intervarices. Fourth whorl: appearance of weak P1 cord. Fifth whorl: no change. Sixth whorl: P1-P4 marked, P5-P6 weak, s1, s2, s6, P6 not atrophied, s1-s2, s6 weak; ADP, MP and ABP weak. Axial sculpture eroded on two early whorls. From third last whorl: three varices and one intervarix intercalated. Higher relief of intervarices on P2. Varices lamellose, slightly winged. Appearance of P1 spine on third whorl, no other spines adapically. On last whorl P1 spine short, straight, slightly bent adaxially. On last whorl growth lamellae erect giving scabrous aspect to shell surface. Ovate aperture up to 29% of diameter and up to 78% of length of last whorl (including siphonal canal). Columellar lip smooth, narrow, slightly erect anteriorly, forming very slightly curved inductura at base. Parietal lip adherent. Outer lip with simple, weak denticles including ID, D1 to D6. Siphonal canal narrow, open, straight, up to 59% of apertural length. Pseudoumbilicus narrow.
COMPARISONS
This species was previously identified as Timbellus fusoides (Deshayes, 1865) by Merle et al. (2011: pl. 101, fig. 5a, b). Nevertheless, attribution to Murex fusoides is problematic, as the type material on which that Bartonian species is based is poorly preserved. It corresponds to two syntypes housed in the collection of the University Lyon (no. UCBL-EM 33383-84; Fig. 11E). The largest is a strongly eroded specimen with most of its axial sculpture, particularly its winged varices lost. This loss of sculpture gives the shell an artificially fusiform shape. The second specimen is smaller and also strongly eroded, but P1 spine is rather turned adapically as in some Timbellus tripteroides (Lamarck, 1822) and its aperture resembles that of T. tripteroides. We designate herein this smaller specimen (UCBL-EM 33384; Fig. 11F, G) as the lectotype of M. fusoides. Therefore, M. fusoides can be regarded as a possible junior synonym of T. tripteroides or a nomen dubium as it is impossible to clearly identify a species based on the type material. Moreover, Bartonian specimens from the Paris Basin identified as T. fusoides are present in several collections housed in the MNHN (e.g., Faullummel, Pons and Schtrock colls). Examination of these specimens shows them to represent eroded T. tripteroides (probably reworked from the Lutetian) or to large and eroded Pterochelus contabulatus (Lamarck, 1803). The type material of T. longicanalis n. sp. comes exclusively from the upper Lutetian of Normandy. It is very well preserved and its delicate and winged varices are not eroded. Thus, its fusoid shape is not due to a post-mortem alteration. The species differs from T. tripteroides by having more staged and more quadrate whorls, more adaxially oriented P1 spines, a straighter siphonal canal, a less rounded aperture, and by having weaker internal denticles and spiral cords.
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 pages 514-516, DOI: 10.5252/geodiversitas2024v46a15, http://zenodo.org/record/13985760