''Frechites'' is an early

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

, a kind of cephalopod with an external shell, included in the

ceratitid Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammoni ...

family Beyrichitidae.

Taxonomic revision

J.P. Smith, 1932, put ''Frechites'' in the Ceratididae where it remained included in the

Treatise A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject and its conclusions."Treat ...

Part L. It was later removed to the Beyrichitidae, established by Spath, 1934.

Comparative morphology

The shell of ''Frechites'' is robust, involute, and strongly ribbed. The outer whorl embraces most of the inner, leaving a small umbilicus. Short, strong ribs appear along the umbilical shoulder that split in twos and threes in the middle of the sides, which continue to the outer, or ventrolateral, shoulder but do not cross the venter, or outer rim, which is left smooth. The suture of ''Frechites'' is partly ammonitic, with a slightly serrate first lateral saddle. The other saddles in the suture are rounded and smooth. As such this is intermediate between common Ceratitidae with entirely ceratite sutures -smooth saddles, serrate lobes, and the normal Beyrichideae with sutures that tend to be ammonitic or subammonitid, with deep serrated lobes and high serrated saddles.

''References''

Frechites -Paleobio
* Treatise on Invertebrate Paleontology, Part L, 1957. Geological Society of America and University Kansas Press. * J.P. Smith, 1932. Lower Triassic Ammonoids of North America. U.S. Geological Survey Professional Paper 167. Ceratitoidea Triassic ammonites Ceratitida genera Fossils of Svalbard {{Svalbard-stub