Trigonoceras

Trigonoceras
Temporal range: Lower Carboniferous
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Nautilida
Superfamily: Trigonocerataceae
Family: Trigonoceratidae
Genus: Trigonoceras
M'Coy,(1844)

Trigonoceras is an extinct prehistoric nautiloid genus from the nautilid family Trigonoceratidae that lived during the Early Carboniferous in what is now western Europe.

Trigonoceras has a very loosely coiled gyroconic or cyrtoconic shell with a subtriangular cross section, as indicated by fragmentary specimens. The venter on the outer rim or convex side is broad and transversely concave with angular shoulders; the sides which converge on a narrow dorsum are broadly convex. The siphuncle is slightly dorsal of the center and is orthochoanitic.(Kummel,B.1964.) A member of the Trigonoceratidae, Trigonoceras is also a component of the superfamily Trigonocerataceae


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