Tetragonoceratidae

The Tetragonoceratidae is a small family of nautilitids constituting a part of the superfamily Tainocerataceae in which shells are coiled with a generally quadrate whorl section. Coiling is either gyroconic or evoluute with a slight dorsal impression. Flanks diverge from the umbilical to the ventral shoulders so as to make the whorl sections widest close to the venter. Nodes made develop on the flanks and shoulders. The siphuncle is tubular, typically found near the venter. Sutures are with lateral lobes and may possess dorsal and ventral lobes as well.

Tetragonoceratidae
Temporal range:
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Nautilida
Superfamily: Tainoceratoidea
Family: Tetragonoceratidae
Flower, 1945

The Tetragonoceratidae, which is an early offshoot of the Rutoceratidae, contains three genera (as of 1964), all confined to the Middle Devonian: Tetragonoceras, Nassauoceras, and Wellsoceras.

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