''Dieneria'' is a genus of

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 ...

ammonoid 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) ...

cephalopods from the Late Triassic of western North America with a smooth discoidal shall of which the venter is truncate and the suture simple. Only the first lateral lobe is slightly serrated, the other lobes entire (smooth) ''Dieneria'', named by Hyatt and Smith, 1905, was first found in the

Carnian The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic Series (or earliest age of the Late Triassic Epoch). It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by t ...

of California and is now also known from British Columbia. According to the American

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, 1957, ''Dieneria'' belongs to the Carnitidae, a component family of the

Ceratitaceae Ceratitoidea, formerly Ceratitaceae, is an ammonite superfamily in order Ceratitida characterized in general by highly ornamented or tuberculate shells with ceratitic sutures that may become goniatitic or ammonitic in some offshoots. (Arkell ' ...

. Subsequently, ''Dieneria'' was reassigned to the Klamathitidae Tozer, 1994, included in the

Pinacocerataceae Pinacoceratoidea, formerly Pinacocerataceae, are generally smooth, compressed, evolute to involute ammonoids from the Triassic, belonging to the Ceratitida, in which the suture is ammonitic, with adventitious and auxiliary elements. As presently ...

References

* Arkell, et al., 1957. Mesozoic Ammonoidea, Treatise in Invertebrate Paleontology, Part L (L157). Geological Society of America. * ''Dieneria'' entry in the Paleobiology Databas

Pinacocerataceae Triassic ammonites of North America Ceratitida genera Late Triassic life {{Ceratitida-stub