Parabolbinella coeni

1983 a Falsipollex sp. Groos, 1969; Milhau: 351. 1985 Falsipollex? sp.; Coen: pl. I, fig. 5. 1988 Falsipollex? sp. 3 G; Milhau: 486, pl. 55, fig. 10. 1990 Parabolbinella? sp.; Casier in Casier & Préat: pl. 1, fig. 8.

2013 b Parabolbinella coeni Casier; Maillet et al.: figs. 7 M – N. 2013 Parabolbinella coeni Casier; Casier in Casier & Préat: 487, pl. II, fig. 4.

Description. Large preplete, bilobate and equivalve carapace. Hmax at 2 / 5 anterior; Lmax at 1 / 3 dorsal; Wmax corresponding to the anterior lobe (L 2). Straight hinge line and dorsal margin. Anterior cardinal angle of about 130 °. Posterior cardinal angle of about 95 ° with a possible spine pointing upwards (not preserved). Anterior margin more rounded than the posterior one. Anterior part of the carapace higher than the posterior one. Ventral margin regularly convex. Well-rounded and large posterior lobe (L 3), reaching the dorsal margin in lateral view. Smaller anterior lobe (L 2), located more ventrally and slightly elliptic with a major axis perpendicular to the dorsal margin. Marked adductorial sulcus. Tecnomorphic carapaces with two adventral spines on each valve. Surface papillose.

Diagnosis. Casier in Casier et al. (2011 a, p. 77).

Discussion. Our specimens show all the features of P. coeni, with a large and well rounded posterior lobe, a possible spine at the postero-dorsal angle and a papillose surface. Only tecnomorphic specimens have been collected, exhibiting two adventral robust spines, one antero-ventral and the other medio-ventral. Occurrence. Lower to Middle Givetian (Hanonet, Trois-Fontaines, Terres d’Haurs, Mont d’Haurs, Névremont Fms, and Fromelennes Fm, Flohimont and Moulin Boreux Mbs), Ardenne (Flohimont, Cul d’Houille, Mont d’Haurs, Aisemont, Resteigne, Couvin, Hotton, Glageon and Aisne section); Middle Givetian (Candás Fm), Asturias (Peran-Perlora section); Givetian, Boulonnais; Middle Devonian, Ruhr.

Material. 2 specimens (1 C, 1 V).