Meekoceras

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Meekoceras
Temporal range: Olenekian
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Meekoceras.jpg
Meekoceras at the New Mexico Museum of Natural History and Science
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Meekoceras

Hyatt, 1879

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

Contents

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 tubercles, spines, or spiral ridges. Umbilicus variable, body chamber short. Sutures ceratitic with smooth rounded saddles and serrated lobes.

Taxonomic position

Smith (1932) [1] and Arkell et al. (1957) [2] 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.

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<span class="mw-page-title-main">Gymnitidae</span> Extinct family of ammonites

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Inyoites is an ammonoid genus from the Lower Triassic, included in the ceratitid family Inyoitidae.

The Hungaritidae comprises a family of ceratitid ammonites described in the Treatise,(Arkell et al. 1957), as involute compressed, discoidal, with keeled or sharpened venter, smooth to weakly costate. Sutures ceratitid, usually with numerous elements.

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Clypeoceras is a genus of ammonites with an involute discoidal shell from the Lower Triassic.

Eophyllites is a genus of ammonoid cephalopods from the Lower Triassic and a predecessor of genera like Monophyllites and Ussurites.

References

  1. Smith, James P. (1932). "Lower Triassic Ammonoids of North America" (PDF). US Geological Survey Professional Paper 167: 1−199. doi:10.3133/pp167.
  2. Arkell, W.J.; Furnish, W. M.; Kummel, B.; Miller, A. K.; Moore, R. C.; Schindewolf, O. H.; Sylvester-Bradley, P. C.; Wright, C. W. (1957). "Part L—Mollusca 4, Cephalopoda, Ammonoidea". In R.C. Moore (ed.). Treatise on Invertebrate Paleontology . Geological Society and University of Kansas Press. ISBN   0-8137-3012-0.