| Gryponautilus Temporal range: Late Triassic
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|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Nautilida |
| Family: | †Grypoceratidae |
| Genus: | †Gryponautilus Mojsisovics, 1902 |
Gryponautilus is a genus of Upper Triassic nautilids (generally coiled nautiloid cephalopods) belonging to the trigonoceratacean family Grypoceratidae, characterized by involute, inflated shells, which at maturity develop narrowly rounded keel-like venters. Venters on inner whorls are truncated and broadly convex to concave.
Immature forms bear a resemblance to Grypoceras.