Cyrtocerinidae
Appearance
Cyrtocerinidae Temporal range: Ordovician
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | Nautiloidea |
Order: | †Cyrtocerinida |
Family: | †Cyrtocerinidae Flower, 1946 |
Genera | |
Cyrtocerinidae is a family of nautiloid cephalopods in the Order Cyrtocerinida,[1] previously considered ellesmerocerids.[2] Members of the family have slightly endogastric (inwardly curved) breviconic shells with ventral siphuncles that have connecting rings thickened as lobes that project straight into the interior.[2]
Cyrtocerinidae was established by Flower 1964[2] for the genus Cyrtocerina Billings 1865, found at various locations across North America. The shells are generally small, laterally compressed, and dorsum more narrowly rounded than the venter.[2]
References
[edit]- ^ Mutvei, Harry (2015-07-03). "Characterization of two new superorders Nautilosiphonata and Calciosiphonata and a new order Cyrtocerinida of the subclass Nautiloidea; siphuncular structure in the Ordovician nautiloid Bathmoceras (Cephalopoda)". GFF. 137 (3): 164–174. doi:10.1080/11035897.2015.1061592. ISSN 1103-5897. S2CID 41162554.
- ^ a b c d Flower, Rousseau H. (1964). "The nautiloid order Ellesmeroceratida (Cephalopoda)" (PDF). New Mexico Bureau of Mines and Mineral Resources Memoir. 12: 1–164.