Pentameroceras
Appearance
Pentameroceras Temporal range: M Silurian
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Scientific classification ![]() | |
Domain: | Eukaryota |
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
[edit]- 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