''Beyrichoceras'' is a genus belonging to the goniatitid family

Muensteroceratidae Muensteroceratidae is one of nine families of the Pericycloidea superfamily. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloid Nau ...

, Paleobiology Database -Beyrichoceratoides
/ref> a group of

ammonoids Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

, extinct shelled cephalopods related to

belemnites Belemnites may refer to: *Belemnitida, an extinct order of cephalopods commonly known as "belemnites" *Belemnites (genus), ''Belemnites'' (genus), a belemnite genus from the Early Jurassic {{disambiguation ...

and recent

coleoids Coleoidea or Dibranchiata is one of the two subclasses of cephalopod molluscs containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e. octopus, squid and cuttlefish). Unlike its extant sister group Nautiloidea ...

and more distantly to the

nautiloids Nautiloids are a group of cephalopods (Mollusca) which originated in the Late Cambrian and are represented today by the living ''Nautilus'' and ''Allonautilus''. Fossil nautiloids are diverse and species rich, with over 2,500 recorded species. Th ...

Description

''Beyrichoceratoides'' has a smooth involute discoidal shell with a very narrow umbilicus, non-crenulate biconvex growth lines, and well-developed ventro-lateral salients and deep hyponomic sinus.GONIAT
online The ventral lobe of the suture is moderately narrow and straight sided; bifurcated with short prongs separated by a low median saddle. The first lateral and umbilical lobes are like those of ''Beyrichoceras'', broad and V-shaped, only the first lateral one is more symmetrical in ''Beyrichoceratoides''. The internal dorsal and flanking lobes are also like those of ''Beyrichoceras'' but with the flanking lobes set relatively further apart.Miller, Furnish, and Schindewolf, 1957, Paleozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Mollusca 4.

Derivation and taxonomy

''Beyrichoceratoides'' was derived from '' Muensteroceras'' near the beginning of the Carboniferous (early Mississippian)Evolution of Complexity in Paleozoic Ammonoid Sutures
Supplementary Material. Saunders,Work, and Nikolaeva. and is included in the Muesteroceratidae, a family assigned to the Goniatitid superfamily

Pericyclaceae Pericycloidea is one of seventeen superfamily (zoology), superfamilies of the Goniatitina suborder. They are an extinction, extinct group of ammonite, ammonoid, which are shelled cephalopods related to squids, belemnites, octopus, octopodes, and ...

. Beyrichoceratoides was named by Bisat in 1924, based on Goniatites implicatus Phillips, 1836. Schindewolf, 1951, considered Beyrichoceratoides equivalent to ''Münsteroceras'' Hyatt 1884 as also presented in the

Treatise A treatise is a Formality, formal and systematic written discourse on some subject concerned with investigating or exposing the main principles of the subject and its conclusions."mwod:treatise, Treatise." Merriam-Webster Online Dictionary. Acc ...

Part L, 1957. Ruzhentsev, 1960, considered ''Beyrichoceratoide'' a distinct genus as do Korn 2006 and Nikolaeva 2008.

Distribution and range

''Beyrichoceratoides'' has been found in the Lower Carboniferous (Mississippian). of Great Britain

Paleoecology

''Beyrichoceratoides'' has been described as a "fast-moving nektonic carnivore". However, its somewhat globular discoidal form suggest a small stalking or hovering nektonic or nekto-benthic ambush predator capable of sudden swift movements to either grab prey or escape predation. As with all known cephalopods, Beyrichoceratoides was undoubtedly carnivorous.

References

{{Taxonbar, from=Q4900234 Goniatitida genera Pericyclaceae Mississippian ammonites Ammonites of Europe