Uranoceratidae


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.

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. 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. Genera include: