Nassauoceras
Nassauoceras is a tetragonoceratid nautiloid from the Middle Devonian of Europe, the shell of which is evolute with a wide, deep umbilicus, slight dorsal impression, low arched venter, rounded ventral shoulders, and flanks that converge dorsally so as to produce a subtrigonal whorl section. Nodes are present on the ventral shoulders. Sutures have shallow ventral and lateral lobes. The siphuncle is near the ventral margin.
| Nassauoceras Temporal range: Middle Devonian | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Nautilida |
| Family: | †Tetragonoceratidae |
| Genus: | †Nassauoceras Miller, 1932 |
Nassauoceras differs from Tetragonoceras in that the latter is gyroconic with a subquadrate whorl section and angular ventral shoulders, but is somewhat similar to Wellsoceras in which whorls are in contact in the early growth stages and shoulders are also rounded.
References
- Bernhard Kummel, 1964. Nautiloidea-Nautilida; Treatise on Invertebrate Paleontology, Part L. R.C. Moore & Curt Teichert, eds. Geological Society of America, pub 1964.
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