Anthracoceratites sp.

Dernov, Vitaly, 2022, Late Bashkirian Ammonoids From The Mospyne Formation Of The Donets Basin, Ukraine, Fossil Imprint 78 (2), pp. 489-512 : 497

Anthracoceratites sp.

Text-fig. 7a

M a t e r i a l. One poorly preserved specimen from stratigraphic level 4 of the Mospyne Formation.

D e s c r i p t i o n. Specimen IGSU-4/3634 is a fragment of a fully sideritized specimen with ~ 16.2 mm diameter ( Text-fig. 7a ). The conch has a closed umbilicus, narrow and strongly convex venter; it merges imperceptibly into broad flattened flanks. The surface of the conch is covered with frequent and very thin growth lines. These run as a biconvex course and form a narrow, deep external sinus and a rather high projection on the ventrolateral shoulder. They form a shallow, broad sinus on the flank and a low projection near the umbilical margin. On the midflank the growth lines are spaced about 0.3 to 0.5 mm apart. The aperture has the same shape as the growth lines.

O c c u r r e n c e. Late Bashkirian, Mospyne Formation; Donets Basin ( Ukraine).

Figures

Text-fig. 7. Ammonoids from the Mospyne Formation. a: Anthracoceratites sp., lateral view; specimen IGSU-4/3634. b, c: Cymoceras sp., lateral view (b), fragment of the suture line in a 42 mm diameter conch (c); specimen IGSU-4/573. d, e: Neodimorphoceratidae indet., lateral view (d), surface ornamentation on the flank (e); specimen IGSU-4/5350. Scale bars 10 mm.