Ceratosaurus was a carnivorous theropod dinosaur that lived in the Late Jurassic period. The genus was first described in 1884 by American paleontologist Othniel Charles Marsh based on a nearly complete skeleton discovered in Garden Park, Colorado, in rocks belonging to the Morrison Formation. The type species is Ceratosaurus nasicornis.
Ornithomimus is a genus of ornithomimid theropod dinosaurs from the Campanian and Maastrichtian ages of Late Cretaceous Western North America. Ornithomimus was a swift, bipedal dinosaur which fossil evidence indicates was covered in feathers and equipped with a small toothless beak that may indicate an omnivorous diet. It is usually classified into two species: the type species, Ornithomimus velox, and a referred species, Ornithomimus edmontonicus. O. velox was named in 1890 by Othniel Charles Marsh on the basis of a foot and partial hand from the Denver Formation of Colorado. Another seventeen species have been named since then, though almost all of them have been subsequently assigned to new genera or shown to be not directly related to Ornithomimus velox. The best material of species still considered part of the genus has been found in Alberta, representing the species O. edmontonicus, known from several skeletons from the Horseshoe Canyon Formation. Additional species and specimens from other formations are sometimes classified as Ornithomimus, such as Ornithomimus samueli from the earlier Dinosaur Park Formation.
Richardoestesia is a morphogenus of theropod dinosaur teeth, originally described from the Late Cretaceous of what is now Canada, the United States and Kazakhstan. It currently contains two species, R. gilmorei and R. isosceles, and a possible third, R. asiatica. It has been used as a morphotaxon to describe other theropod teeth widely displaced in time and space from the type species. If all teeth assigned to the genus are truly reflective of the animals biology and taxonomic state, it would have been one of the longest lasting dinosaur genera, perhaps also being the most widely distributed.
Lambeosaurus is a genus of hadrosaurid dinosaur that lived during the Late Cretaceous period of western North America. The first skull of Lambeosaurus described was used by palaeontologist Lawrence M. Lambe to justify the creation of the new genus Stephanosaurus, but it was shown that this skull had to belong to a separate taxon, which William A. Parks named Lambeosaurus lambei in 1923, to honour Lambe. Multiple further species of Lambeosaurus have been named since, including L. clavinitialis and L. magnicristatus in 1935, and L. laticaudus in 1981 which was later moved to its own genus Magnapaulia. It has also been identified that some of the species of the genera Tetragonosaurus and Corythosaurus are juveniles of Lambeosaurus, including T. praeceps, T. cranibrevis, and C. frontalis. Lambeosaurus is the eponymous member of its subfamily Lambeosaurinae and tribe Lambeosaurini. Lambeosaurins, which also includes Corythosaurus and Hypacrosaurus from western North America, are understood to be some of the most specialized ornithopods.
Camptosaurus is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America and possibly also Europe. The name means 'flexible lizard'.
Thescelosaurus is a genus of ornithischian dinosaur that lived during the Late Cretaceous period in western North America. It was named and described in 1913 by the paleontologist Charles W. Gilmore; the type species is T. neglectus. Two other species, T. garbanii and T. assiniboiensis, were named in 1976 and 2011, respectively. Additional species have been suggested but are currently not accepted. Thescelosaurus is the eponymous member of its family, the Thescelosauridae. Thescelosaurids are either considered to be basal ("primitive") ornithopods, or are placed outside of this group within the broader group Neornithischia.
Edmontonia is a genus of panoplosaurin nodosaurid dinosaur from the Late Cretaceous Period. It is part of the Nodosauridae, a family within Ankylosauria. It is named after the Edmonton Formation, the unit of rock where it was found.
Polyodontosaurus is a potentially dubious genus of troodontid dinosaur named in 1932 by Charles W. Gilmore for a left dentary from the Dinosaur Park Formation. It had been considered a synonym of Stenonychosaurus or Troodon for a significant time, before being declared a nomen dubium. The only known species is the type, P. grandis.
Thespesius is a dubious genus of hadrosaurid dinosaur from the late Maastrichtian-age Upper Cretaceous Lance Formation of South Dakota.
Chungkingosaurus, meaning "Chongqing Lizard", is a genus of herbivorous dinosaur from the Late Jurassic Upper Shaximiao Formation in what is now China. It is a member of the Stegosauria.
Panoplosaurus is a genus of armoured dinosaur from the Late Cretaceous of Alberta, Canada. Few specimens of the genus are known, all from the middle Campanian of the Dinosaur Park Formation, roughly 76 to 75 million years ago. It was first discovered in 1917, and named in 1919 by Lawrence Lambe, named for its extensive armour, meaning "well-armoured lizard". Panoplosaurus has at times been considered the proper name for material otherwise referred to as Edmontonia, complicating its phylogenetic and ecological interpretations, at one point being considered to have existed across Alberta, New Mexico and Texas, with specimens in institutions from Canada and the United States. The skull and skeleton of Panoplosaurus are similar to its relatives, but have a few significant differences, such as the lumpy form of the skull osteoderms, a completely fused shoulder blade, and regularly shaped plates on its neck and body lacking prominent spines. It was a quadrupedal animal, roughly 5 m (16 ft) long and 1,600 kg (3,500 lb) in weight. The skull has a short snout, with a very domed surface, and bony plates directly covering the cheek. The neck had circular groups of plates arranged around the top surface, both the forelimb and hindlimb were about the same length, and the hand may have only included three fingers. Almost the entire surface of the body was covered in plates, osteoderms and scutes of varying sizes, ranging from large elements along the skull and neck, to smaller, round bones underneath the chin and body, to small ossicles that filled in the spaces between other, larger osteoderms.
Gilmoreosaurus is the name given to a genus of dinosaur from the Cretaceous of Asia. The type species is Gilmoreosaurus mongoliensis. It is believed to be a hadrosaur or iguanodont from the Iren Dabasu Formation of Inner Mongolia, dating to 96 Ma ago. Additional specimens have been described as distinct species, including G. atavus from the Khodzhakul Formation of Uzbekistan and G. arkhangelskyi from the Bissekty Formation. However, these are based on very fragmentary remains, and their classification is dubious. An additional species, G. kysylkumense is sometimes included, though it has also been referred to the related genus Bactrosaurus.
Laosaurus is a genus of neornithischian dinosaur. The type species, Laosaurus celer, was first described by O.C. Marsh in 1878 from remains from the Oxfordian-Tithonian-age Upper Jurassic Morrison Formation of Wyoming. The validity of this genus is doubtful because it is based on fragmentary fossils. A second species from the Morrison Formation, L. gracilis, and a species from the late Cretaceous Allison Formation of Alberta, Canada, Laosaurus minimus, are also considered dubious.
Charles Whitney Gilmore was an American paleontologist who gained renown in the early 20th century for his work on vertebrate fossils during his career at the United States National Museum. Gilmore named many dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus ovatus and Thescelosaurus.
Bennettazhia is a genus of tapejaromorph pterosaur which lived during the Albian stage of the Early Cretaceous from what is now the Hudspeth Formation of the state of Oregon in the United States. Although originally identified as a species of the pteranodontoid pterosaur Pteranodon, Bennettazhia is now thought to have been a different animal. The type and only species is B. oregonensis.
Hadrianus is an extinct genus of tortoise belonging to the Testudinidae found in the United States, the Yolomécatl Formation of Mexico, the Alai Beds of Kyrgyzstan and Spain and believed to be the oldest true tortoise known. The genus is thought to be closely related to the genus Manouria. The genus may have evolved in the subtropics of Asia and subsequently migrated to North America and Europe. Evangelos Vlachos (2018) reassessed the North American species attributed to the genus, and determined only two as accepted namely H. corsoni & H. majusculus. The remaining species were identified as either junior synonyms, moved to other genera or considered nomen dubium do to incomplete fossils.
Cteniogenys is a genus of choristodere, a morphologically diverse group of aquatic reptiles. It is part of the monotypic family Cteniogenidae. The type and only named species, C. antiquus, was named in 1928 by Charles W. Gilmore. The holotype, VP.001088, was collected in the Morrison Formation, Wyoming in 1881 by William H. Reed. More specimens have been discovered since then, including specimens from the Late Jurassic of Portugal and Middle Jurassic of Britain, which have not been assigned to species.
Ototriton is an extinct genus of rhineurid amphisbaenian or worm lizard from the Early Eocene of the western United States, including the type and only species Ototriton solidus. Paleontologist F. B. Loomis named Ototriton in 1919 on the basis of a single skull from the Wind River Formation in Wyoming, misinterpreting it as the skull of a salamander. Unlike salamanders and like other rhineurids, Ototriton has a shovel-shaped snout that it presumably used for burrowing underground. Ototriton is one of the earliest known rhineurids and also one of the largest.
Alcovasaurus, alternatively known as Miragaia longispinus, is a genus of herbivorous stegosaurian dinosaur that lived in the Late Jurassic. It was found in the Morrison Formation of Natrona County, Wyoming, United States. The type species is Stegosaurus longispinus, later given the genus Alcovasaurus.
Aciprion is an extinct genus of lizard from the Middle Oligocene of Colorado, Wyoming and Nebraska. It was named in 1873 by American paleontologist Edward Drinker Cope for a jaw fragment from the Cedar Creek Member of the White River Formation in Colorado, as the binomial A. formosum. Multiple additional specimens have been referred to the genus, including the second species A. majus named by Gilmore in 1928 for a partial skull. However, the differences between A. formosum and A. majus relate to slight size differences, so A. majus is considered a junior synonym of A. formosum. Cope originally named Aciprion as a genus of teiid lizard, but Gilmore reclassified it as a member of Iguanidae.
