Crassimurex Merle, 1990

Genus Crassimurex Merle, 1990 View in CoL

TYPE SPECIES. — Murex calcitrapoides Lamarck, 1822 by original designation (synonym of Murex calcitrapa Lamarck, 1803 ). Middle Eocene (Lutetian and Bartonian): Paris and Loire basins, France.

COMMENTS ON SUBFAMILIAL PLACEMENT

Members of this genus display a biconic shell with a moderately high spire, spiny varices on P1, internal denticles

(D1 to D6), a broad and open siphonal canal, a sinus of P1, around 8-10 varices, and complex spiral sculpture including the primary cords P1 to P6 (convex part of the whorl) and ADP-MP (siphonal canal). In addition, their shape is similar to that of Poirieria Jousseaume, 1880 or Flexopteron (see Merle et al. 2011). For these reasons, Merle et al. (2011) placed Crassimurex ( s. s.) and Crassimurex ( Eopaziella) Gürs, 2001 in an informal group named basal muricids. It is still impossible to place this genus within a subfamily using shell characters. Obervations on Crassimurex ( s. s.) calcitrapa Lamarck, 1803 at La Ferme de l’Orme (Lutetian, Paris Basin) suggest this species was a drilling predator ( Merle et al. 2024), but this ability occurs in different subfamilies (e.g., Muricinae and Ocenebrinae ) and does not help in subfamilial attribution.