Discoceras
| Discoceras Temporal range: M-U Ordovician
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|---|---|
| Scientific classification Edit this classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | †Tarphycerida |
| Family: | †Trocholitidae |
| Genus: | †Discoceras Barrande, 1867 |
Discoceras is an extinct marine cephalopod mollusk, a member of the Trocholitidae in the Tarphycerida. It is distinct from Discosorus , It is characterized by closely coiled, gradually expanding shells with a subquadrate cross section, that may be ribbed or smooth. The sides are broadly rounded; the venter is wide and slightly rounded. The maximum width is slightly dorsal of the middle. The dorsum has a slight to moderate impression. The siphuncle starts off central for the first half whorl then becomes marginodorsal in the succeeding two whorls, then subdorsal at maturity. As with Trocholites , the dorsal siphuncle in Discoceras probably indicates an orientation during life that places the back of the living chamber high in the shell.[1]
Discoceras has been found in Middle and Upper Ordovician sediments in Northern Europe, Baffin Island in Canada, Yunnan and Hubei provinces in China, and in Punjab, India.
See also
[edit ]References
[edit ]- ^ Discoceras, p K360 in Vol K of the Treatise on Invertebrate Paleontology in the section on the Trocholitidae, pp K359-K362, in the Chapter on the Tarphycerida by Furnish and Glenister starting with page K343.
- Tarphycerida
- Ordovician cephalopods
- Ordovician cephalopods of Europe
- Ordovician cephalopods of North America
- Ordovician animals of Asia
- Extinct animals of India
- Middle Ordovician first appearances
- Late Ordovician extinctions
- Paleozoic life of Manitoba
- Paleozoic life of the Northwest Territories
- Paleozoic life of Nunavut