Xiphogymnites is an extinct ammonoid cephalopod genus from the Triassic included in the family Gymnitidae. It is known from the Balkans in eastern Europe.
Anderssonoceras is a genus of small, smooth ammonites with a flared umbilical shoulder, like Prototoceras, assigned to the ceratitid family Anderssonoceratidae as the type, but once included in the Otoceratidae.
Arctohungarites is a genus of Triassic ammonoids now placed in the ceratitid family Danubitidae, but previously included in the Hungeritidae.
Badiotites is a genus of extinct ammonoid cephalopods belonging to the ceratitid family Badiotitidae. It was previously included with Lecanites in the Lecanitidae, a family formerly of the Clydonitaceae but reassigned by Tozer (1981) to the Danubitaceae. The Badiotitidae is included in the Ceratitaceae.
Dobrogeites is a genus of ammonoids from the order Ceratitida, included in the family Megaphyllitidae that produced evolute compressed planispiral shells with rounded venters, inner whorls ornamented as in Tirolites, outer whorls smooth, suture with multiple smooth lobes; Initially found in Anisian sediments in Romania.
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.
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, the remaining having been added.
Xenoceltitidae are evolute, generally ribbed, upper Lower Triassic Ceratitida with ceratitic or goniatitic sutures; formerly included in the Noritaceae but now placed in the Xenodiscaceae.
Paraceltitidae is a family of Middle and Upper Permian cephalopods, that comprise the earliest of the Ceratitida. Paraceltitidids have variably ribbed, discoidally evolute shells with compressed elliptical whorl sections and simple suture lines. Their origin is most likely in the Daraelitidae of the Prolecanitida and they are the apparent source of the Xenodiscidae. All together they lived for some 12 million years, from about 270.6 to about 258 million years ago.
Ammonitina comprises a diverse suborder of ammonite cephalopods that lived during the Jurassic and Cretaceous periods of the Mesozoic Era. They are excellent index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods.
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 ammonitic but goniatic in a few offshoots.
The Tropitidae is a family of Upper Triassic Ammonoidea belonging to the Tropitaceae, a superfamily of the Ceratitida
Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the venter.
Gymnites is a genus of ammonoid cephalopod from the Middle Triassic belonging to the ceratitid family Gymnitidae. These nektonic carnivores lived during the Triassic period, Anisian age.
Gymnitidae is a family of Lower to Middle Triassic ammonite cephalopods with evolute, discoidal shells.
Hildoceratidae is a family of ammonoid cephalopods from the Lower Jurassic, lower Pliensbachian to lower Bajocian substages, generally with strongly ribbed, involute shells. They are combined with the Hammatoceratidae, Graphoceratidae, and Sonniniidae to make up the Hildoceratoidea.
Perisphinctidae is a family of Middle and Upper Jurassic discoidal ammonites in the order Ammonitida. They have a shell morphology that is mostly evolute, typically with biplicate, simple, or triplicate ribbing. Large forms have simple apertures and smooth body chambers while small forms have lappets and ribbed body chambers.
Hammatoceratoidea, formerly Hammatocerataceae was a superfamily of middle Jurassic ammonites erected by Schindewolf in 1964 that combined the families Graphoceratidae, Hammatoceratidae, and Sonniniidae. The three families were previously included in the Hildoceratoidea, however subsequent classifications have moved the families back into Hildoceratoidea.
Leymeriellidae is a family of Lower Cretaceous ammonites comprising rather small forms distinguished from Hoplitidae by their flattened and grooved ribs and virtual absence of umbilical tubercles. The family is derived from the Desmoceratidae. Leymeriella schrammeni anterior has evolved from Desmoceras keilhacki keilhacki.
Protrachyceras is a genus of ceratitid ammonoid cephalopods belonging to the family Trachyceratidae.
