Uranoceratidae

Uranoceratidae
Temporal range: ?Late Ord - Mid Sil
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: †Tarphycerida
Suborder: †Barrandeocerina
Family: †
Hyatt in Zittel, 1900
Genera

See text

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:

References

  1. ^ a b Flower, R.H. & Kummel, B. 1950. A Classification of the Nautiloidea. Journal of Paleontology vol 24, no.5, pp604–616, Sept 1950.
  2. ^ a b Sweet, Walter C, 1964. Nautiloidea - Barrandeocerida, in Treatise on Invertebrate Paleontology, Part K, Geol Soc of America, Teichert & Moore(eds).
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