• Source: Trematoceras

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




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.




Distribution


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




References

Kata Kunci Pencarian:

• Trematoceras
• Orthoceratidae
• Paris biota
• 2024 in paleomalacology
• Besano Formation
• 2016 in paleomalacology
• Pseudotemperoceras
• List of prehistoric nautiloid genera
• 2020 in paleomalacology