Beyrichoceras is a genus belonging to the goniatitid family Maxigoniatitidae[1] that lived during the Mississippian Period (Early Carboniferous)
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.
Beyrichoceras is assigned to the Maximitidae,[1] [3] although some authors have assigned it to the Muensteroceratidae or Anthracoceratidae.[4] Miller and Furnish [2] included Beyrichoceras in the subfamily Goniatitinae, family Goniatitidae, and superfamily Goniatitaceae. The Maxigoniatitidae, established by Korn, Klug & Mapes, 1999, is based on Goniatites maximus var. saourensis Pareyn, 1961, renamed Maxigoniatites
Beyrichoceras is found in middle Lower Carboniferous (Mississippian upper Osagean-Meremacian equivalent) strata [4] in North America, Europe, and North Africa.[2] [3]
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.