Cyrtobaltoceras is an extinct cephalopod genus known from the upper Lower Ordovician Fort Cassin Formation at Valcour, N.Y. that is included in the Nautiloid family Baltoceratidae
Cyrtobaltoceras Temporal range:
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Order: | †Orthocerida |
Family: | †Baltoceratidae |
Genus: | †Cyrtobaltoceras Flower (1964) |
Taxonomy edit
Cyrtobaltoceras was named by Flower (1964 [1] who then assigned it to the Baltoceratidae which at that time was included in the Ellesmerocerida. The Baltoceratidae, along with included genera, has since been moved to the Orthocerida.[2]
Morphology edit
The genotype, Cyrobaltoceras gracile Flower, is based on a small, slender, incomplete, 25 mm long shell with a slight exogastric curvature. Sutures form lobes across the ventral side but go transversely straight across the dorsum. The siphuncle is proportionally large, almost half the shell diameter in width, and lies against the ventral margin.
Retention edit
The holotype of Cyrtobaltoceras gracile, Reusseau Flower's no. 341, is housed in the paleontological collection of the New Mexico Museum of Natural History and Science in Albuquerque, N.M (U.S.A)
References edit
- Fossils (Smithsonian Handbooks) by David Ward