Timbellus magnei
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 magnei

description: Timbellus magnei n. name
(Figs 12 A-F; 26G-I)
Murex trigonus Rouault, 1850: 204, pl. XVII, fig. 17a [non Murex trigonus Gmelin, 1791].
Pterynotus trigonus – Glibert 1963: 11 [non Murex trigonus Gmelin, 1791].
Pterynotus tricarinatus trigonus – Merle 1990: 158, pl. 2, figs 13, 14 only [non Murex trigonus Gmelin, 1791].
Pterynotus tripteroides – Merle 1990: 156, pl. 3, fig. 1 only [non Lamarck, 1822].
Timbellus tripteroides – Merle et al. 2011: 44, pl. 100 figs 3, 4 only [non Lamarck, 1822].
Timbellus crenulatus palensis – Merle et al. 2011: 440, pl. 98, fig. 1 only [non Magne, 1941].
TYPE MATERIAL. — Neotype. France • Aquitaine Basin, Pyrénées-Atlantiques, Bos d’Arros; uppermost part of the Marnes de Gan only (top biozone N12/base biozone NP13); Early Eocene (Ypresian); BMNH 69802 (Seaman coll.) designated by Merle (1990: 158, pl. 2, fig. 14) (Fig. 12A).
ADDITIONAL MATERIAL. — France • 1 spm Aquitaine Basin, Pyrénées-Atlantiques, Gan (Tuilerie); uppermost part of the Marnes de Gan only (top biozone N12/base biozone NP13); Early Eocene (Ypresian, uppermost part of the Marnes de Gan); MNHN.F.A32506 (Merle coll.), figured specimen of Merle et al. (2011: pl. 100, fig. 3) • 1 spm; idem; MNHN.F.A32508 (Merle coll.), figured specimen of Merle et al. (2011: pl. 100, fig. 1) (Figs 12C, D; 26G) • 1 spm; idem; MNHN.F.R61437, Merle coll., figured specimen of Merle (1990: pl. 3, fig. 1) • 1 spm; idem; MNHN.F.A24115 (Merle coll.) • 2 spm; idem; MNHN.F.A72443 (Varone coll.) (Figs 12E, F; 26I) • 35 spm; idem; MNHN.F.A24114 (Merle coll.) • 1 spm (juvenile with protoconch); idem; MNHN.F.A90545 (Merle coll.) (Figs 12B; 26H).
TYPE HORIZON. — Uppermost part of the Marnes de Gan only (top biozone N12/base biozone NP13), see Nolf et al. (2002: 173, fig. 4), Early Eocene (Ypresian).
TYPE LOCALITY. — France, Aquitaine Basin, Pyrénées-Atlantiques, Bos d’Arros (Nolf et al. 2002: 185).
DISTRIBUTION. — Known from the type locality and Gan (tuilerie), Aquitaine Basin (France), early Eocene (Ypresian).
DESCRIPTION
Smooth, multispiral protoconch of 3.5 whorls (Figs 12B; 26H). Sinusigeral scar well marked.Teleoconch up to 46 mm in height, up to 39 mm in width, subfusiform in profile, composed of eight whorls. Moderately high spire. Last whorl up to 70% of total length. Apical angle 53° excluding wings, 70° including wings. Spiral sculpture with marked primary cords on varices and intevarices. First whorl: no cord. Second whorl: appearance of weak P1, P2 and s1. Third whorl: P1, P2, s1 well marked; appearance of s2 weak. Fourth whorl: s2 well marked. From fifth to seventh whorl: no change or appearance of threads. Eighth whorl: P1 to P6, s1, s2, s3 (well developed), P6; ADP, MP weak or missing on siphonal canal. First whorl:around ten protovarices.Second whorl: appearance of varices, three varices and two intervarices between. From third to last whorl, three to five low intervarices. Higher relief of intervarices on P2. Varices lamellose and strongly winged. Appearance of short P1 spine on second whorl.P1 spine short, almost included in wing. No other cord spines. Ovate aperture up to 22% of diameter and up to 71% of length of last whorl (including siphonal canal). Columellar lip smooth, narrow, erect anteriorly, forming curved inductura at base. Parietal lip slightly adherent. Outer lip with well developed internal denticles including ID, D1 to D6. D1 and D2 bifid. Outer lip not crenulate. Siphonal canal narrow, open, straight, up to 57% of apertural length. Pseudoumbilicus narrow.
COMPARISONS
Rouault (1850) described from Bos d’Arros (a locality very close to Gan), Murex trigonus based on juvenile specimens. Unfortunately, Murex trigonus Rouault, 1850 is a junior homonym of Murex trigonus Gmelin, 1791 and Magne (1941), a homonymy as yet uncorrected. Therefore, we propose the new name Timbellus magnei n. name herein. The juvenile specimens illustrated by Rouault (1850) are characterized by low intervarices varying from three to five (compare Fig. 12C, D and G). This character is present on the early whorls of the adults of T. tripteroides sensu Merle (1990: pl. 2, figs 13, 14 only). Thus, one can accept that these large T. tripteroides sensu Merle (1990) correspond to adult specimens of T. magnei n. name. Timbellus magnei n. name is easily separated from typical T. tripteroides by having a multispiral protoconch (Fig. 12B), whilst typical tripteroides has a paucipiral protoconch (see Fig. 8D, E) and by having more and lower intervarices.
Cossmann & O’Gorman (1923) misinterpreted Murex trigonus sensu Rouault and illustrated a specimen typical of the genus Ponderia: P. daguini (Magne, 1941). In addition, Cossmann & O’Gorman (1923) described and figured an adult specimen of Timbellus that Cosmann named Murex cf. tricarinatus Lamarck, 1803. Magne (1941) gave the name Murex (Pteropurpura) palensis to Murex cf. tricarinatus Lamarck, 1803 (sensu Cossmann 1923) and demonstrated that the juvenile specimens illustrated by Rouault (1850) as Murex trigonus were not juveniles of Murex (Pteropurpura) palensis. We discovered a young specimen from Gan differing from the juveniles of T. magnei n. name. It displays one high intervarix between each varix (Fig. 12G), a character also present on the early teleoconch whorls of well preserved adults of T. palensis (Fig. 12H, I). Douvillé & O’Gorman (1929: pl. 29, fig. 1) figured a specimen from the early Eocene of Biron (near Orthez) and called it Murex tripteroides. That specimen bears one high intervarix between each varix and possibly represents T. palensis.
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 516-517, DOI: 10.5252/geodiversitas2024v46a15, http://zenodo.org/record/13985760