Timbellus de Gregorio, 1885

Merle, Didier, Pacaud, Jean-Michel, Ledon, Daniel & Goret, Bernard, 2024, New Cenozoic Muricidae (Mollusca: Gastropoda) from Europe, Geodiversitas 46 (15), pp. 495-551 : 510

Genus Timbellus de Gregorio, 1885

TYPE SPECIES. — Murex latifolius Bellardi, 1873 , by subsequent designation ( Vokes 1964: 14). Middle Miocene: Italy.

COMMENTS ON THE SUBFAMILIAL PLACEMENT

Historically, fossil and Recent members of Timbellus have usually been attributed to the genus Pterynotus Swainson, 1833 (e.g., Cossmann 1889; Cossmann & Pissarro 1911; Glibert 1963; Vokes 1970) in the subfamily Muricinae . Based on molecular data, Barco et al. (2010, 2012) studied the phylogenetic relationships of Pterynotus Swainson, 1833 represented by P. elongatus (Lightfoot, 1786) and P. fulgens Houart, 1988 and Pterymarchia Houart, 1995 represented by P. martinetana (Röding, 1798) . These authors demonstrated firstly, that Pterynotus and Pterymarchia are not phylogenetically close to P. fulgens Houart, 1988 and secondly, none of these taxa are included within the clade of the Muricinae . According to Merle et al. (2011), Pterynotus fulgens is closely related to the type species of Timbellus and is now attributed to that genus. Thus, Merle et al. (2011) and Houart (2018) excluded Timbellus from the Muricinae , but did not give a subfamilial attribution. Russini et al. (2023: 866) place Timbellus in incertae sedis and considered it likely to represent an independent lineage worthy of subfamilial rank.

SPECIES GROUP OF T. TRIPTEROIDES ( LAMARCK, 1822)

In order to delineate different lineages included in Pterynotus (s.s.), Harasewych & Jensen (1979) and more recently Vokes (1992) defined five “species groups” for the Western Atlantic Region. With the exception of the typical group of Pterynotus [species group of Pterynotus pinnatus (Swainson, 1822) ], the four other species groups are members of the genus Timbellus ( Merle et al. 2011) . Merle et al. (2011: 130) added a fifth group to Timbellus : the species group of T. tripteroides ( Lamarck, 1822) . Members of that group display a strong development of the internal denticles within the outer lip and their shell shape is narrower than those belonging to the group of T. crenulatus (Röding, 1798) . Fine growing lamellae forming a scabrous surface are usually missing and only reported in T. capitaneus Pacaud, Ledon & Goret, 2017 . The following new species described herein, T. magnificus n. sp., T. occidentalis n. sp., T. calciacus n. sp., T. longicanalis n. sp. and T. magnei n. name (for Murex trigonus Rouault, 1850 , non Murex trigonus Gmelin, 1791 ) display features allowing a placement in this species group. Several of these new species ( T. occidentalis n. sp., T. calciacus n. sp., T. longicanalis n. sp. and T. magnei n. name) are superficially similar to, and mistaken for, T. tripteroides in the past. Moreover, the type material of T. tripteroides is lost, as it is missing in the Lamarck’s collections in Geneva and Paris. In order to avoid future taxonomic mistakes, we designate a neotype herein (MNHN.F.A90546, coll. of the Club géologique d’Île-de-France, Fig. 6B, C ). The type material of Lamarck was collected at Grignon (middle Lutetian) and the neotype is selected from the same type locality (precisely Falunière of Grignon; Calcaire à Orbitolites complanatus Formation, biozone NP15, see Gély & Lorenz 1991). The neotype was chosen to closely represent the specimen illustrated by Lamarck (1805: pl. 3, fig. 4; Fig. 6A ). It displays rounded wings, P1 spine is included in the wings and is not protruding. This morphology of the anterior part of the wings ( Fig. 6D ) differs from that of the Murex tripteroides illustrated by Deshayes (1835: pl. 82, figs 1, 2; Fig. 6E, F ) and Cossmann & Pissarro (1911: pl. 34, 169-1), which display a well individualized P1 spine ( Fig. 6G, H ). We examined numerous specimens from different localities in the Paris Basin and found transitional forms between the two morphotypes. Thus, we consider this difference to fall within the intraspecific variation.

Figures

FIG. 6. — Neotype, historical figures, spiral cords and denticles of the outer lip in T. tripteroides (Lamarck, 1822): A-D, morphotype with rounded varices and poorly distinguishable P1 spine; E-H, morphotype with easily distinguishable P1 spine: A, original figure of Lamarck (1805: pl. 3, fig. 4); B, C, neotype designated herein, MNHN.F.A90546 (Club géologique d'Île-de-France leg.), Thiverval-Grignon (Falunière), Yvelines, Paris Basin, France, middle Eocene (Lutetian); D, MNHN.F.A90552 (Pacaud coll.), Chaussy (Les Garennes),Paris Basin, France,middle Eocene (Lutetian); E, F, figured specimen of Deshayes (1835: pl. 82, fig. 1-2); G, H, figured specimen of Cossmann & Pissarro (1911: pl. 35, fig. 169-1; MNHN.F.J10350 (Cossmann coll.), Chaussy (Les Garennes). Scale bars: 20 mm. Credits: B-D, P. Loubry MNHN/CNRS; G, H, J. Mouchart.