Eosomichelinoceras

Eosomichelinoceras Temporal range: Ordovician 461–452 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	†Orthocerida
Family:	†Baltoceratidae
Genus:	†Eosomichelinoceras Chen (1974)

Eosomichelinoceras is an extinct genus from the actively mobile carnivorous cephalopod family Baltoceratidae that lived in what would be Asia and South America during the Ordovician from 461—452 mya, existing for approximately 9 million years.[1]

Taxonomy

Eosomichelinoceras was named by Chen (1974)[1] Its type is Eosomichelinoceras huananense. It was assigned to Orthocerida by Chen (1974); and to Baltoceratidae by Kröger et al. (2007).[2]

Morphology

Eosomichelinoceras is a smooth or transversally lirate slender, orthoconic baltoceratid with a narrow, tubular siphuncle,[3] located between the center and the edge of the shell. Connecting rings are thin, septal necks orthochoanitic, and without known endosiphuncular or cameral deposits.

Distribution

Fossils of Eosomichelinoceras have been found in Argentina, China and Iran.[1]

References

1. Eosomichelinoceras at Fossilworks.org
2. J. Y. Chen. 1974. Ordovician Nautiloidea. A Handbook of the Stratigraphy and Paleontology in Southwest China 138-143
3. B. Kröger, M. S. Beresi, and E. Landing. 2007. Early orthoceratoid cephalopods from the Argentine Precordillera (Lower-Middle Ordovician). Journal of Paleontology 81(6):1266-1283

Further reading

• Fossils (Smithsonian Handbooks) by David Ward