Melvilloceras NASSICHUK , 1975

Dernov, Vitaly, 2022, Late Bashkirian Ammonoids From The Mospyne Formation Of The Donets Basin, Ukraine, Fossil Imprint 78 (2), pp. 489-512 : 498

Genus Melvilloceras NASSICHUK, 1975

T y p e s p e c i e s. Melvilloceras sabinensis NASSICHUK, 1975 ; by original designation.

D i a g n o s i s. Genus of the family Surenitidae with discoidal to pachyconic conch with moderately involute and rather narrow umbilicus. The venter is narrowly rounded and flanks are broadly rounded or flattened. Ornamentation is delicately reticulate and with umbilical nodes on the early growth stages; sinuous growth lines more conspicuous than longitudinal lirae; four to six constrictions per whorl. The external suture is characterized by ventral prongs that are attenuate and are separated from one another by a secondary ventral saddle that is greater than half the height of the broadly rounded first lateral saddle. The first lateral lobe is broad and pointed with straight or slightly curved sides (after Nassichuk 1975).

S p e c i e s i n c l u d e d. M. sabinensis NASSICHUK, 1975 , Canadian Arctic Archipelago ( Canada); M. rotaii (LIBROVITCH in POPOV, 1979), Donets Basin ( Ukraine).

S t r a t i g r a p h i c r a n g e. Late Bashkirian.