Kingdom Animalia Class Cephalopoda Order Oncocerida Rank Genus | Phylum Mollusca Subclass Nautiloidea Family Acleistoceratidae | |
Similar Cyrtoceras, Nautilida, Nautiloid | ||
Gonatocyrtoceras is a genus of oncocerid nautiloids belonging to the family Acleistoceratidae, that lived during the Middle Devonian. Gonatocyrtoceras is characterized by strongly curved, depressed, breviconic shells. Curvature is exogastric, meaning the lower, or ventral, side is convex in longitudinal profile. The aperture is without a hyponomic sinus. The siphuncle is small and subventral.
Other Devonian Acleistoceratidae are Acleistoceras, Paracleistoceras, and Poteriocerina.
References
Gonatocyrtoceras Wikipedia(Text) CC BY-SA