Gomphoceras is a questionable nautiloid cephalopod genus assigned to the Oncocerida. The family to which it might belong is undetermined.

Gomphoceras
Temporal range: Middle Silurian
Scientific classification
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undetermined
Genus:
Gomphoceras

Sowerby, 1839

Gomphoceras, named by Sowerby in 1839, is generally short but rapidly expanding, straight to slightly endogastric, with a gibbous body chamber such that all sides are convex. The aperture as vertically transverse, with a hyponomic sinus on a low spout-like process and a larger rounded dorsal sinus connetected above.

Tetrameroceras and Trimeroceras, both oncocerids, are similar in general form, but have more complex apertures.

References

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  • Sweet (1964). R.C. Moore (ed.). Part K, Mollusca 3. Treatise on Invertebrate Paleontology. Lawrence, Kansas: Geological Society of America and University of Kansas Press. p. K190–K216.