Beyrichoceratoides

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Beyrichoceratoides
Temporal range: L Carboniferous (Mississippian)
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Beyrichoceratoides

Bisat 1924

Beyrichoceras is a genus belonging to the Goniatitid family, Muensteroceratidae, [1] a group of ammonoids, extinct shelled cephalopods related to belemnites and recent coleoids and more distantly to the nautiloids

Contents

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. [2] 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. [3]

Derivation and taxonomy

Beyrichoceratoides was derived from Muensteroceras near the beginning of the Carboniferous (early Mississippian) [4] and is included in the Muesteroceratidae, a family assigned to the Goniatitid superfamily Pericyclaceae. [1] [2]

Beyrichoceratoides was named by Bisat in 1924, based on Goniatites implicatus Phillips, 1836. [2] Schindewolf, 1951, considered Beyrichoceratoides equivalent to Münsteroceras Hyatt 1884 as also presented in the Treatise Part L, 1957. Ruzhentsev, 1960, considered Beyrichoceratoide a distinct genus as do Korn 2006 and Nikolaeva 2008. [2]

Distribution and range

Beyrichoceratoides has been found in the Lower Carboniferous (Mississippian). [4] of Great Britain [1]

Paleoecology

Beyrichoceratoides has been described as a "fast-moving nektonic carnivore". [1] 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.

Related Research Articles

Goniatite Extinct order of molluscs

Goniatids, informally goniatites, are ammonoid cephalopods that form the order Goniatitida, derived from the more primitive Agoniatitida during the Middle Devonian some 390 million years ago. Goniatites (goniatitids) survived the Late Devonian extinction to flourish during the Carboniferous and Permian only to become extinct at the end of the Permian some 139 million years later.

<i>Goniatites</i> Extinct genus of molluscs

Goniatites is a genus of extinct cephalopods belonging to the family Goniatitidae, included in the superfamily Goniatitaceae. Hibernicoceras and Hypergoniatites are among related genera.

<i>Beyrichoceras</i> Genus of molluscs (fossil)

Beyrichoceras is a genus belonging to the Goniatitid family, Maxigoniatitidae that lived during the Mississippian Period

Uraloceras is an ammonoid cephalopod genus belonging to the goniatitid family Paragastrioceratidae. The genus was named by Ruzhencev 1936 and is a jr. synonym of Pseudogastrioceras Spath 1930 according to Miller, Furnish and Schindeworlf, 1957. More recent classifications however list the two as distinct genera and put Uraloceras in the Paragastrioceratinae and Pseudogastrioceras in the Pseudogastrioceratinae.

Dimeroceratidae is one of three families in the Dimeroceratoidea, a goniatid superfamily included in the Ammonoidea; extinct shelled cephalopods with adorally convex septa and usually narrow ventro-marginal siphuncles.

Prolobitidae is a family of middle and upper Devonian ammonoid cephalopods currently included in the goniatitid suborder Tornoceratina and superfamily Dimeroceratoidea, but previously included in the ancestral Anarcestida.

Cheiloceratidae is a family of ammonoid cephalopods included in the goniatitid suborder Tornoceratina in which the suture has 4 to 12 lobes, the ventral one undivided and those in the lateral areas originating as subdivisions of internal and external lateral saddles.

Gastrioceratoidea Extinct superfamily of molluscs

Gastrioceratoidea is one of seventeen superfamilies in the suborder Goniatitina, ammonoid cephalopods from the Late Paleozoic.

Texoceras is an extinct ammonoid genus in the monotypic goniatitid subfamily Texoceratinae, included in the family Adrianitidae. These are shelled cephalopods more closely related to squids, belemnites, octopuses, and cuttlefish than to nautiloids from which they are derived.

Cyclolobidae Family of molluscs (fossil)

Cyclolobidae: Goniatitid Ammonoidea belonging to the Cycloloboidea with thickly discoidal to subgloblar shells with a small but open umbilicus and ammonitic sutures with numerous lobes that have subparallel sides.

Thalassoceratidae a family of late Paleozoic ammonites included in the goniatitid superfamily Thalassoceratoidea along with the Bisatoceratidae. Some eight genera are included, although the specific number and exactly which depends on the particular classification.

Medlicottiidae is a family of ammonoid cephalopods belonging to the Prolecanitida, known from the Upper Carboniferous (Pennsylvanian) to the Early Triassic.

Prolecanitida is an order of extinct ammonoid cephalopods with discoidal to thinly lenticular shells with goniatitic or ceratitic sutures and which retained the simple retrochoanitic siphuncle with backward extending septal necks. As typical for ammonoids the siphuncle is along the ventral margin. Prolecanitids form a relatively small and stable order within the Ammonoidea with 43 named genera and about 1250 species, but with a long-ranging lineage of about 108 m.y. stretching from the Lower Carboniferous to the Triassic. Although not as diverse as their goniatitid contemporaries, the Prolecanatida provided the stock from which all later Mesozoic ammonoids were derived.

Agoniatitida Extinct order of molluscs

Agoniatitida, also known as the Anarcestida, is the ancestral order within the cephalopod subclass Ammonoidea originating from bactritoid nautiloids, that lived in what would become Africa, Asia, Australia, Europe, and North America during the Devonian from about the lower boundary of Zlichovian stage into Taghanic event during upper middle Givetian, existing for approximately 25 million years.

<i>Cyclolobus</i>

Clyclolobus is a smooth, essentially involute subdiscoidal goniatitid ammonoid that has sutures with a bifurcate ventral lobe, flared outwardly at the end, in which the halves may be secondarily trifurfate, ending in sharp, narrow projections. Lateral sutural elements follow an acuate line that swings first to the front, then sharply to the rear before becoming hidden by the next whorl. Saddles are narrow, cumulous in appearance with short, irregular, rounded sub-endings. Ventro-lateal lobes are trifurcate with pointed, thorn-like projections.

Pachylyroceras is a large, generally subglobular, Upper Mississippian gonitite and included in the cephalopod subclass Ammonoidea.

Cravevoceras is an Upper Paleozoic ammonite in the goniatite family Cravenoceratidae, probably derived from Pachylyroceras and contemporary with other cravenoceratid genera like Caenolyroceras, Tympanoceras and later Alaoceras and Lyrogoniatites. It is also a member of the Neoglyphiocerataceae.

The Uddenitinae a subfamily of the Medlicottiidae, a family of ammonoid cephalopods included in the Prolecanitida. The Uddenitinae, proposed by Miller and Furnish, and known from the Pennsylvanian and Lower Permian, are transitional between the ancestral Pronoritidae and the more traditional medlicottiids

The Medlicottiinae is a subfamily of the Medlicottiidae, a family of ammonoid cephalopods included in the Prolecanitida, characterized by having discoidal to thinly lenticular shells with a retuse (grooved) venter and sutures with bifid auxiliary lobes.

Pronorites is a prolecanitid genus from the middle and upper Carboniferous, upper Mississippian and Pennsylvanian. Distribution is wide spread.

References

  1. 1 2 3 4 Paleobiology Database -Beyrichoceratoides
  2. 1 2 3 4 GONIAT online
  3. Miller, Furnish, and Schindewolf, 1957, Paleozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Mollusca 4.
  4. 1 2 Evolution of Complexity in Paleozoic Ammonoid Sutures, Supplementary Material. Saunders,Work, and Nikolaeva.