Ceratitida is an order that contains almost all

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) ...

cephalopod genera from 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 ...

as well as ancestral forms from the Upper

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

, the exception being the phylloceratids which gave rise to the great diversity of post Triassic

ammonites 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) ...

. Ceratitids overwhelmingly produced planospirally coiled discoidal shells that may be evolute with inner whorls exposed or involute with only the outer whorl showing. In a few later forms the shell became subglobular, in others, trochoidal or uncoiled. Sutures are typically ceratitic, with smooth saddles and serrate or digitized lobes. In a few the sutures are goniatitic while in others they are ammonitic.

Taxonomy

* Ceratitida **

Ceratitoidea 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 ...

Choristoceratoidea Choristoceratoidea, formerly Choristocerataceae, is a superfamily of Late Triassic ceratitidan ammonites Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly ...

Clydonitoidea Clydonitoidea, formerly Clydonitaceae, is a superfamily in the ammonoid cephalopod order Ceratitida characterized by generally costate and turberculate shells with smooth, grooved, or keeled venters and sutures that are commonly ceratitic or ammon ...

Danubitoidea The Danubitoidea is a large and diverse superfamily in the order Ceratitida of the Ammonoidea that combines five families removed from the Ceratitaceae, Clydonitaceae, and Ptychitaceae. Taxonomy Superfamily Danubitoidea * Family Aplococeratidae ...

Dinaritoidea Dinaritoidea is an extinct superfamily of ammonoids in the order Ceratitida 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 ...

** Lobitoidea ** Meekoceratoidea ** Megaphyllitoidea ** Nathorstitoidea **

Noritoidea Noritoidea, formerly Noritaceae, is an extinct superfamily of cephalopods belonging to the Ammonite order Ceratitida. Noritoidea, defined by Karpinsky in 1889, combines ceratitids with "typically smooth, more or less discoidal shells with rou ...

Otoceratoidea Otoceratoidea, formerly Otocerataceae, is an extinct superfamily of ammonite cephalopods in the order Ceratitida Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the ...

Pinacoceratoidea 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 ...

Ptychitoidea Ptychitoidea, formerly Ptychitacheae, is a superfamily of typically involute, subglobular to discoidal Ceratitida in which the shell is smooth with lateral folds or striations, inner whorls are globose, and the suture is commonly ammonitic. Their ...

** Sageceratoidea **

Tropitoidea Tropitoidea, formerly Tropitaceae, is an extinct superfamily of ammonite cephalopods in the order Ceratitida, containing the following families: * Didymitidae * Episculitidae *Haloritidae The Haloritidae is a family of subglobular, involute, ...

Xenodiscoidea Xenodiscoidea, formerly Xenodiscaceae, is a superfamily within the ammonoid order Ceratitida. The superfamily was named by Frech in 1902, presently contains ten families, only one of which was included in the original Otocerataceae of Hyatt, 1900 ...

Only eight superfamilies are shown in the

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

, Part L,(1957), the Otocerataceae, Noritaceae, Ceratitaceae, Arcestaceae, Clydonitaceae, Lobitaceae, Ptychitaceae, and Tropitaceae, in text sequence. The other 10 have been added since, derived from within the original eight.

References

* Arkell et al., 1962, Mesozoic Ammonoidea.

part L, Mollusca 4, Ammonoidea. R.C. Moore (ed)
Paleobiology Database
Lopingian first appearances Late Triassic extinctions Mollusc orders {{Ceratitida-stub