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.
| Gonatocyrtoceras Temporal range: Middle Devonian
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| Genus: | Gonatocyrtoceras Foerste, 1926
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Other Devonian Acleistoceratidae are Acleistoceras, Paracleistoceras, and Poteriocerina.
References
edit- R.C. Moore, ed. (1964). Part K, Mollusca 3. Treatise on Invertebrate Paleontology. Lawrence, Kansas: Geological Society of America and University of Kansas Press. p. K190–K216.
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