Baculites is an extinct genus of heteromorph ammonite cephalopods with almost straight shells. The genus, which lived worldwide throughout most of the Late Cretaceous, and which briefly survived the K-Pg mass extinction event, was named by Lamarck in 1799.
Inoceramus is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous.
Ancyloceras is an extinct genus of heteromorph ammonites found throughout the world during the Lower Cretaceous, from the Lower Barremian epoch until the genus extinction during the Lower Aptian.
Arcestes is a genus of extinct ceratitid ammonites found in Triassic-aged marine strata.
Anisoceratidae is an extinct family of heteromorph ammonites which belong to the Ancyloceratina superfamily Turrilitoidea. Members of the family range is from the lower Albian to the upper Turonian. The family is possibly derived from a member of the Hamitidae.
Ptychodus is a genus of extinct durophagous (shell-crushing) sharks from the Late Cretaceous. Fossils of Ptychodus teeth are found in many Late Cretaceous marine sediments worldwide. Numerous species have been described. The youngest remains date to around 85 million years ago. A large number of remains have been found in the former Western Interior Seaway. A 2016 publication found that Ptychodus are likely true sharks belonging to Selachimorpha, rather than hybodonts or batoids as previously thought. Their life history coincides with the typical life of many other large sharks: they lived relatively long lives and were slow growing and produced large offspring and small litters.
Placenticeras is a genus of ammonites from the Late Cretaceous. Its fossils have been found in Asia, Europe, North and South America.
Douvilleiceras is a genus of ammonites from the Middle to Late Cretaceous. Its fossils have been found worldwide, in Africa, Asia, Europe, and North and South America.
Ogmodirus is an extinct genus of plesiosaur found in the Cenomanian-Turonian Greenhorn Limestone of Kansas. The type species, O. martini, was named by Samuel Wendell Williston and Roy Lee Moodie in 1913.
The Straight Cliffs Formation is a stratigraphic unit in the Kaiparowits Plateau of south central Utah. It is Late Cretaceous in age and contains fluvial, paralic, and marginal marine (shoreline) siliciclastic strata. It is well exposed around the margin of the Kaiparowits Plateau in the Grand Staircase – Escalante National Monument in south central Utah. The formation is named after the Straight Cliffs, a long band of cliffs creating the topographic feature Fiftymile Mountain.
The Carlile Shale is a Turonian age Upper/Late Cretaceous series shale geologic formation in the central-western United States, including in the Great Plains region of Colorado, Kansas, Nebraska, New Mexico, North Dakota, South Dakota, and Wyoming.
Neoptychites is an extinct ammonoid cephalopod genus from the Turonian stage of the Upper Cretaceous, with a worldwide distribution.
Mammites is a Late Cretaceous ammonite genus included in the acanthoceratoidean family, Acanthoceratidae, and the type genus for the subfamily Mammitinae. Mammites was named by Laube and Bruder in 1887.
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.
Calliphylloceras is an ammonite belonging to the Phylloceratidae.
Pachydesmoceras is a genus of ammonites belonging to the family Desmoceratidae.
Pseudoaspidoceras is an extinct genus of ammonites in the family Acanthoceratidae.
Kossmaticeras is an extinct ammonoid genus belonging to the desmoceratacean family Kossmaticeratidae. Species in this genus were fast-moving nektonic carnivores. They lived during the Late Cretaceous, from upper Turonian to upper Maastrichtian age. The type species of the genus is Ammonites theobaldianus.
Dufrenoyia is an extinct genus of Cretaceous ammonites included in the family Parahoplitidae. These fast-moving nektonic carnivores lived in the Cretaceous period. The type species of the genus is Ammonites dufrenoyi.
Watinoceras is a genus of acanthoceratid ammonite that lived during the early Turonian stage of the Late Cretaceous.
