Beyrichites
Encyclopedia
Beyrichites is an extinct genus in the ammonoid cephalopod, order Ceratitida
from the Lower and Middle Triassic of southern Europe, Asia, and western North America.
Beyrichites has an involute, discoidal shell with a narrowly arched venter and signoidal ribbing that tends to disappear on the outer whorl. The suture is subammonitic, meaning the saddles are serrate as well as the lobs.
Two subgenera are recognized: B. (Beyrichites) from the Lower and Middle Triassic, which has no tubercles, and B. (Gangadharites) from the Middle Triassic of the Himalaya which has tbercles on the whorl sides.
Ceratitida
The 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 ammonites....
from the Lower and Middle Triassic of southern Europe, Asia, and western North America.
Beyrichites has an involute, discoidal shell with a narrowly arched venter and signoidal ribbing that tends to disappear on the outer whorl. The suture is subammonitic, meaning the saddles are serrate as well as the lobs.
Two subgenera are recognized: B. (Beyrichites) from the Lower and Middle Triassic, which has no tubercles, and B. (Gangadharites) from the Middle Triassic of the Himalaya which has tbercles on the whorl sides.
References
- Treatise on Invertebrate Paleontology, Part L; Ch. Mesozoic Ammonoidea. Geological Soc of America and U Kansas Press, R.C Moore (ed)