Pseudosirenites
Encyclopedia
Pseudosirenites is an Upper Triassic ammonite belonging to the ceratitid
family Trachyceratidae
, like Sirenites
, but with a narrow outer rim (venter) that has a nodose keel on either side.
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....
family Trachyceratidae
Trachyceratidae
The Trachyceratidae is a family of ceratitid ammonoid cephalopods that lived during the Middle- and Late Triassic characterized by shells that are more or less involute and highly ornamented....
, like Sirenites
Sirenites
Sirenites is an ammonoid cephalopod from the Upper Triassic included in the Ceratitida, and type for the trachyceratid subfamily Sirenitinae....
, but with a narrow outer rim (venter) that has a nodose keel on either side.