Tetragonitidae
From Wikipedia, the free encyclopedia
| Tetragonitidae Temporal range: | |
|---|---|
 | |
| Tetragonites sp., Cretaceous, Madagascar | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | †Ammonoidea |
| Order: | †Ammonitida |
| Suborder: | †Lytoceratina |
| Family: | †Tetragonitidae |
| Subgroups | |
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See text | |
Tetragonitidae is a family of Cretaceous lytoceratin ammonites typically with square or trapezoidal whorl section at least during some growth stage. Members of this family are usually smooth but some lirate or striate, often with constrictions. Other features include suture with a varying number of auxiliary saddles, and an internal suture with two or more. Major saddles are irregularly trifid. The family is derived from the genus Tetragonites.
