Beyrichoceras is a genus belonging to the Goniatitid family, Maxigoniatitidae

Maxigoniatitidae

Maxigoniatitidae is one of nine families of the Pericyclaceae superfamily. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:...

 that lived during the Mississippian Period (Early Carboniferous)

Description

Beyrichoceras can be recognized by its small, thickly discoidal shell

Mollusc shell

The mollusc shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes...

 with small umbilicus, deep dorsal impression, arched flanks and rounded venter The ventral lobe of the suture is bifurcated, wide at its base, narrowing adapically, 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 presently assigned to the Maximitidae, although some authors have assigned it to the Muensteroceratidae

Muensteroceratidae

Muensteroceratidae is one of nine families of the Pericyclaceae superfamily. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:...

 or Anthracoceratidae

Anthracoceratidae

Anthracoceratidae is one of nine families of the Pericyclaceae superfamily. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:...

 . Miller and Furnish included Beyrichoceras in the subfamily Goniatitinae

Goniatitinae

Goniatitinae is one of two subfamilies of the Goniatitaceae superfamilies. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:...

, family Goniatitidae

Goniatitidae

Goniatitidae is one of three families of the Goniatitaceae superfamilies. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:...

, and superfamily Goniatitaceae

Goniatitaceae

Goniatitaceae is one of seventeen superfamilies of the Goniatitina suborder. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopodes, and cuttlefish, and more distantly to the nautiloids.-References:...

. The Maxigoniatitidae, established by Korn, Klug & Mapes, 1999, is based on Goniatites maximus var. saourensis Pareyn, 1961, renamed Maxigoniatites

Distribution and Range

Beyrichoceras is found in midde Lower Carboniferous

Carboniferous

The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 ( Mississippian upper Osagean-Meremacian equivalent) strata in North America, Europe, and North Africa .

Paleoecology

Beyrichoceras has been described as a "fast-moving nektonic carnivore". 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