Stephanoceras is an extinct genus of Stephanoceratoid ammonite which lived during the Bajocian. It is the type genus of the family Stephanoceratidae.
Anaklinoceras is a genus of extinct heteromorph ammonite cephalopod that lived in marine environments in what is now Western North America during the Campanian division of the Cretaceous period. Their shells were very similar to the related ammonites of the genus Ainoceras, where the young ammonite's shell coiled helically, and upon reaching adulthood, the youngest coil arched over the older coils.
Aulacostephanus is an extinct ammonoid cephalopod genus from the Upper Jurassic Tithonian belonging to the perisphinctoidean family Aulacostephanidae.
Arieticeras is an extinct genus of cephalopod belonging to the Ammonite subclass.
Arcestes is a genus of extinct ceratitid ammonites found in Triassic-aged marine strata.
Parapuzosia is an extinct genus of desmoceratid ammonites from the Cenomanian to the Campanian of Africa, Europe, and North America. They are typically very large ammonites, reaching diameters of 60 cm (2.0 ft) or more, with the largest species measuring upwards of more than 2.5 m (8.2 ft). It possesses a moderately involute shell with flat or slightly rounded sides. Distinct primary and secondary ribbing can be observed in the inner whorls.
Austrotrachyceras is a genus of ammonite cephalopod, belonging to the order Ceratitida.
Okribites is a perisphinctoidean ammonite from the middle Jurassic of the Republic of Georgia. It is assigned to the family Parkinsoniidae, a group of strongly but evenly ribbed evolute, commonly discoidal ammonites. Parkinsonia is a related genus.
Exiteloceras is an ammonite genus from the Late Cretaceous.
Promicroceras is an extinct ammonite genus from the upper Sinemurian of Europe, named by Leonard Spath in 1925. Promicroceras is included in the family Eoderoceratidae, which is part of the ammonitid superfamily Eoderoceratoidea.
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 ammonites, which had complex shell shapes and ornamentation, Psiloceras had a smooth shell.
Coroniceras is a genus in the Arietitidae, a family in the ammonitid superfamily Psiloceratoidea, from the lower Sinermurian stage in the Lower Jurassic. It is a sub zone ammonite of the Arnioceras semicostatum Zone.
Eubostrychoceras is a genus of helically wound, corkscrew form, heteromorph ammonite which lived during the Upper Cretaceous. The genus is included in the ancycleratid family Nostoceratidae.
Macroscaphites is an extinct cephalopod genus included in the Ammonoidea that lived during the Barremian and Aptian stages of the Early Cretaceous. Its fossils have been found throughout most of Europe and North Africa.
Pectinatites is an extinct cephalopod genus belonging to the order Ammonoidea, that lived during the upper Tithonian stage of the Late Jurassic. They were fast-moving nektonic carnivores.
Kilianella is a genus of the ammonite family Neocomitidae. The shell of Kilianella is evolute with a slightly grooved venter and covered by strong, gently flexious, single or bifurcating ribs.
Tragophylloceras is an extinct genus of cephalopod belonging to the Ammonite subclass.
Neophylloceras is an extinct genus of cephalopod belonging to the Ammonite subclass.
Metoioceras is an extinct genus of cephalopod belonging to the Ammonite subclass which lived during the Cenomanian.
