Beyregrex Merle, 2024

Merle, Didier, Pacaud, Jean-Michel, Ledon, Daniel & Goret, Bernard, 2024, New Cenozoic Muricidae (Mollusca: Gastropoda) from Europe, Geodiversitas 46 (15), pp. 495-551 : 534

Genus Beyregrex Merle , n. gen.

( Fig. 22 E-H)

urn:lsid:zoobank.org:act:6796AFD5-F7A6-46E7-9293-ADF9A7C8DC80

TYPE SPECIES. — Murex pereger Beyrich, 1854 , late Eocene to late Oligocene: Paris Basin, Belgium, Mainz Basin and north Germany ( Fig. 22G, H ).

ETYMOLOGY. — Name based on the type species Murex pereger Beyrich, 1854 and using Bey (from Beyrich), the letters reg (from pereger ) and rex (from Murex ).

INCLUDED SPECIES. — Murex sarroniensis Carez, 1879 [synonym: Murex abbatiae Wrigley, 1930 ], London and Paris Basins, Paleocene (Thanetian) to Early Eocene (Ypresian) ( Fig. 22C, D ); Murex hantoniensis Edwards in Lowry et al., 1866, Hampshire Basin, England, late Eocene (Priabonian) ( Fig. 22E, F ); M. pereger Beyrich, 1854 [synonym: Murex areolifer Sandberger, 1861 ], Paris Basin, Belgium, Mainz Basin and north Germany, late Eocene (Priabonian) to late Oligocene (Chattian) ( Fig. 22G, H ); Hexaplex brevaculeatus Janssen, 1978 , Paris basin, early Oligocene (Rupelian), Mainz basins, early Oliogocene and North Germany, late Oligocene; Murex (Poirieria) cedillatus Cossmann & Peyrot, 1924 , Aquitaine Basin, France, Early Miocene (Burdigalian).

DIAGNOSIS. — Biconic teleoconch with subangular whorls. D1 well developed. P6 not atrophied. IP weak, ADP, MP present. Varices formed by 1-3 lamellae abaxially turned on the early whorls, occasionally reinforced by several lamellae on the succeeding whorls. P1 spine short. Shoulder sinus widely open, short, moderately deep. Posterior sinus on sutural ramp shallow.Columellar lip usually smooth.

COMMENTS

Members of Beyregrex Merle , n. gen. differ from those of Jsowerbya in having a deeper shoulder sinus, more lamellose varices, and a smooth columellar lip. Pseudotrophonopsis Merle , n. gen. is also distinguishing from Beyregrex Merle , n. gen. in having rounded whorls, strong secondary cords of equal strength to the primary cords, and numerous split internal denticles within the outer lip (D1 to D5). Represented by five species, Beyregrex Merle , n. gen. is the most diverse genus of the group. It extends from the Anglo-Parisian late Paleocene/early Eocene with B. sarroniensis ( Carez, 1879) , n. comb. to the Early Miocene (Burdigalian) from the Aquitaine Basin with B. cedillatus ( Cossmann & Peyrot, 1924) . Beyregrex sarroniensis n. comb. displays several primitive characters, such as missing IP, MP and ABP. During the middle Eocene, no Beyregrex Merle , n. gen. species are known, but the genus re-emerges in the late Eocene of Hampshire with B. hantoniensis (Edwards in Lowry et al., 1866), n. comb.. That species is closely related to B. pereger ( Beyrich, 1854) , n. comb. occurring in the Paris Basin and in Germany (Mainz Basin and north Germany) during the Oligocene. According to Janssen (1978), B. brevaculeatus ( Janssen, 1978) is another species. It was originally described from the Chattian of Germany (at Glimmerode) but is also recorded in the Rupelian of the Paris Basin ( Merle 1999; Lozouet 2012). For the Neogene, B. cedillatus ( Cossmann & Peyrot, 1924) from the Burdigalian of the Aquitaine Basin demonstrates that the genus was not restricted to northern Europe.

Figures

FIG. 22. — Species of the informal group Jsowerbyia-Beyregrex n. gen.-Pseudotrophonopsis n. gen.: A, B, Jsowerbya sexdentata (Sowerby, 1823), BMNH GG22673 (Burton coll.), Colwell Bay, Wight Island, England, late Eocene (Priabonian); C, D, Beyregrex sarroniensis (Carez, 1870), n. comb., MNHN.F.J02576 (figured specimen of Cossmann & Pissarro 1911: pl. 35, fig.169-14), Sarron, Oise, Paris Basin, France, early Eocene (Ypresian); E, F, B. hantoniensis (Edwards, 1866),n. comb.,Morton coll., Middle Headon Brockenhurst bed, Whitecliff Bay, Wight Island, England,late Eocene (Priabonian); G, H, B. pereger (Beyrich, 1854), n. comb.,MNHN.F.A90561 (Lozouet & Maestrati coll.), Auvers-Saint-Georges,Essonne,Paris Basin,France, early Oligocene (Rupelian); I-L, Pseudotrophonopsis defossa (Pilkington, 1804), n. comb.: I, J, MNHN.F.J17634 (Cossmann coll.), Barton-on-Sea, Hampshire, England, middle Eocene (Bartonian); K, A. Smith coll. (juvenile specimen), upper Barton bed H, Barton Highcliffe; L, MNHN.F.A90560 (Munier-Chalmas coll.), Le Vouast, Oise, late Eocene (Priabonian). Scale bars: A-J, L, 5 mm; K, 1 mm. Credits: A, B, D. Serrette (MNHN); C, D, G-J, L, P. Loubry (MNHN/CNRS); E-F, K, A. Morton.