Beyrichoceras
| Beyrichoceras Temporal range: L Carb (M Miss) | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Ammonoidea |
| Order: | Goniatitida |
| Suborder: | Goniatitina |
| Superfamily: | Pericyclaceae |
| Family: | Maxigoniatitidae |
| Genus: | Beyrichoceras Foord 1903 |
Beyrichoceras is a genus belonging to the Goniatitid family, Maxigoniatitidae [1] that lived during the Mississippian Period (Early Carboniferous)
Description
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 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 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
Distribution and range
Beyrichoceras is found in midde 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
- 1 2 3 Paleobioloby-Beyrichoceras 12/08/09
- 1 2 3 Miller, Furnish, and Schindewolf, 1957, Paleozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Mollusca 4.
- 1 2 GONIAT-online 12/08/09
- 1 2 Evolution of Complexity in Paleozoic Ammonoid Sutures, Supplementary Material, Saunders, D. Work,and Nikolaeva. Science magazine