Crassimurex Merle 1990

Genus Crassimurex Merle, 1990 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.