Pentameroceras
| Pentameroceras Temporal range: M Silurian | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Oncocerida |
| Family: | Trimeroceratidae |
| Genus: | Pentameroceras Hyatt, 1884 |
Pentameroceras is a straight to slightly exogastric breviconic oncocerid from the middle Silurian of North America and Europe belonging to the Trimeroceratidae.
This nautiloid cephalopod produced a straight to slightly exogastric shell with a variable cross section that is generally circular, in which septa are close spaced and transverse, the body chamber is inflated. The aperture, which is constricted, consists of a narrow, vertical slit-like opening extending from the ventral hyponomic sinus to a dorsal sinus and two pairs of lateral sinuses that diverge in the upper portion. Siphuncles in the Trimeroceratidae are slender and empty.
References
- Sweet W.C. 1964. Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America and Univ. of Kansas press. Teichert & Moore, (eds)
- Pentameroceras- Paleobio db
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