Fresnosaurus is an extinct genus of plesiosaur from the Late Cretaceous of what is now California. The type species is Fresnosaurus drescheri, first described by Welles in 1943. The generic name Fresnosaurus honors Fresno County, while the specific name honors Arthur Drescher.
Ogmodirus is an extinct genus of plesiosaur with an extremely long neck that lived in the Cretaceous. It may be member of the Elasmosauridae, a group of marine animals related to Elasmosaurus, but the condition of the fossils discovered to date means the genus is dubious. The type species, Ogmodirus martini, was named by Samuel Wendell Williston and Roy L. Moodie in 1913. The original specimen consisted of a pelvic girdle, limb elements, and more than fifty cervical (neck) vertebrae discovered in Cloud County, Kansas. A second species, Ogmodirus ischiadicus, has since been referred to Styxosaurus. Sepkoski (2002) assigned Ogmodirus to the Plesiosauria.
Ungulites is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Askeatonolucidum is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Dawsonocerina is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Devonocheilus is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Kionoceras is an extinct nautiloid cephalopod genus included in the orthocerid family Kionoceratidae with scattered worldwide distribution from the Middle Ordovician to the Lower Permian. Kionoceratids are orthocerids with prominent longitudinal ornamentation on their shells, sometimes augmented by secondary transverse ornamenttion. Orthocerids are, of course, prehistoric nautiloides with generally straight and elongate shells, mostly with central or subcentral siphuncles.
Cyrthoceratites is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Kosovoceras is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Gyroceras is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Faberoceras is an extinct genus of prehistoric nautiloid. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Huroniella is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Ophionautilus is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Eridites is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Antigyroceras is a genus of nautiloids in the order Discosorida, known from central Asia, that lived during Late Silurian and Early Devonian times. It is contemporary with the discosorid Endoplectoceras
Palelialia is an extinct genus of prehistoric nautiloids., a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Belloceras is an extinct genus of prehistoric nautiloid. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Folioceras is an extinct genus of prehistoric nautiloid. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Neptunoceras is an extinct genus of prehistoric nautiloids. The nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Stearoceras is an extinct genus of prehistoric nautiloids from the Lower Pennsylvanian - Lower Permian with a fair worldwide distribution.(Kümmel 1964)
