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]