Trematoceras is an orthoconic nautiloid cephalopod from the Upper Triassic of Europe and Asia named by Eichwald in 1851.

Taxonomy

Trematoceras is included in the Michelinoceratinae, a subfamily of the Orthoceratidae[1]

Morphology

Trematoceras has a slender, subcylindrical shell with a bluntly pointed apex, long chambers, straight transverse sutures, and a smooth or faintly cancellated surface. The siphuncle is central, tubular, and empty; septal necks short, orthochoanitic; connecting rings cylindrical or only faintly expanded. Chambers contain prominent lamellar mural and episeptal deposits.[1]

Distribution

Trematoceras has been found in Upper Triassic sediments in Afghanistan, Kazakhstan, and the Russian Federation.[2]

References

  1. ^ a b Sweet, W.C. 1964. Nautiloidea- Orthocerida. Treatise on Invertebrate Paleontology, Part K. Geol. Soc. of America and Univ Kansas Press
  2. ^ Trematoceras -Paleobio db
Allikas: https://en.wikipedia.org/wiki/Trematoceras
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