Beyrichoceras

Beyrichoceras Temporal range: L Ma PreꞒ Ꞓ O S D C P T J K Pg N [1]
Fossil shells of Beyrichoceras from Visean of Madagascar (Erfoud )
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	†Ammonoidea
Order:	†Goniatitida
Family:	†Maxigoniatitidae
Genus:	†Beyrichoceras Foord, 1903

Beyrichoceras is a genus belonging to the

Beyrichoceras can be recognized by its small, thickly discoidal shell with small umbilicus, deep dorsal impression, arched flanks and rounded venter ^[2] The ventral lobe of the suture is bifurcated, wide at its base, narrowing apically, ending in a pair of outwardly turned prongs separated by a low median saddle. The first lateral lobe is similar in size to the ventral lobe; broad, V-shaped, and more or less symmetrical. The umbilical lobe, like the first lateral lobe, is broad, V-shaped, and fairly symmetrical, only much shallower. The dorsal lobe is long and narrow, closely flanked by narrow internal lobes.

Taxonomic position

Beyrichoceras is assigned to the Maximitidae,

Beyrichoceras is found in middle Lower Carboniferous ( Mississippian upper Osagean-Meremacian equivalent) strata ^[4] in North America, Europe, and North Africa.^[2][3]

Paleoecology

Beyrichoceras has been described as a "fast-moving nektonic carnivore".^[1] Its small, involutely coiled form nevertheless suggest a floating nektonic or nekto-benthic stalker capable to sudden swift maneuvering. As with all known cephalopods, Beyrichoceras was undoubtedly carnivorous.

References