Psiloceratidae is an extinct family of

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s belonging to the

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) ...

subclass.

Description

The Psiloceratidae are evolute, smooth or with blunt primary ribbing. The venter is rounded and generally smooth, in some feebly keeled. Sutures are simple with phylloid saddle endings in some. The aptychus is single, found in sutu in Psiloceras

Genera

* '' Badouxia'' Guex and Taylor, 1976 * ''

Caloceras ''Caloceras'' is an extinct genus of cephalopod belonging to the 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 mor ...

'' * '' Discamphiceras'' * '' Euphyllites'' Wahner, 1898 * '' Franziceras'' Buckman, 1923 * ''

Kammerkaroceras ''Kammerkaroceras'' is an extinct cephalopod genus from the Lower Jurassic belonging to the ammonoid family Psiloceratidae Psiloceratidae is an extinct family of cephalopods belonging to the ammonite subclass. Description The Psiloceratidae a ...

'' * ''

Laqueoceras ''Laqueoceras'' is an extinct genus of cephalopod belonging to the Ammonite subclass. They were fast-moving nektonic Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by Ge ...

'' * '' Murihikuites'' Stevens, 2004 * '' Paradiscamphiceras'' Taylor, 1988 * '' Paraphylloceras'' Salfeld, 1919 * ''

Psiloceras ''Psiloceras'' is an extinct genus of ammonite. ''Psiloceras'' is among the earliest known Jurassic ammonites, and the appearance of the earliest ''Psiloceras'' species form the definition for the base of the Jurassic. Unlike most earlier ammoni ...

'' * ''

Psilophyllites ''Psilophyllites'' is an extinct genus of cephalopod belonging to the 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, ar ...

Distribution

Fossils of species within this genus have been found in the

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 ...

rocks of Canada, in the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

rocks of Argentina, Austria, Canada, China, France, Germany, Hungary, Mexico, New Zealand, Spain), United Kingdom, United States, as well as in the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

of Australia and Russia.

References

* Arkell, W.J.; Kummel, B.; Wright, C.W. (1957). Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Lawrence, Kansas: Geological Society of America and University of Kansas Press. Ammonitida families Psiloceratoidea Rhaetian first appearances Maastrichtian extinctions {{Ammonitina-stub