“Meekoceras”的意思、由来-开放百科全书

词条

Meekoceras

释义

Description
Taxonomic position
References

{{Italic title}}{{Taxobox
| fossil_range = Early Triassic (Scythian)
| image =
| regnum = Animalia
| phylum = Mollusca
| classis = Cephalopoda
| subclassis = Ammonoidea
| ordo = Ceratitida
| superfamilia = Noritoidea
| familia = Meekoceratidae
| subfamilia = Meekoceratinae
| genus = Meekoceras
| genus_authority = Hyatt, 1879
}}

Meekoceras is a genus of ceratitid ammonites with a discoidal shell that lived during the Early Triassic Period.

Description

Meekoceras is characterized by a compressed, discoidal, evolute or involute shell with flattened sides and narrow, flattened or rounded venter that is without keels or furrows. The surface is smooth or with lateral folds, but no subercles, spines, or spiral ridges. Umbilicus variable, body chamber short. Sutures ceratitic with smooth rounded saddles and serrated lobes.

Taxonomic position

Smith (1932) and Arkell et al. (1957) included Meekoceras in the Meekoceratidae, which was named to contain the genus. Different approaches were made regarding the next taxonomic level. Arkell, et al. (1957) includes Meekoceratidae in the Noritacdeae while Smith (1932) included them in the Prolecanitoidea.

Wyoningites and Svalbardiceras are related genera.

References

Arkell, W.J. et al., 1957. Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology Part L. Geological Society and University of Kansas Press.
Smith, J.P. 1932. Lower Triassic Ammonoids of North America. US Geological Survey Professional Paper 167.

4 : Meekoceratidae|Ammonites of North America|Ceratitida genera|Triassic ammonites

随便看

开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。