Uranoceratidae
Appearance
This article may be too technical for most readers to understand.(December 2013) |
Uranoceratidae | |
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Scientific classification | |
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Family: | Uranoceratidae Hyatt in Zittel, 1900
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Genera | |
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The Uranoceratidae is a family of Silurian barrandeoceroids that tend to become uncoiled with age and in which siphuncle segments tend to be expanded into the camerae.[1]
Description
Shells of uranoceratids are gyroconic. Early stages of a few species are annulated. Later stages of all are smooth or faintly striated or cancellated.[2] In many, septal necks are straight, but in others recumbent on one side or the other. Connecting rings are thin.
Derivation and content
The Uranoceratidae are derived from Bickmorites.[1] Genera include: