Trachodon is a dubious genus of hadrosaurid dinosaur based on teeth from the Campanian-age Upper Cretaceous Judith River Formation of Montana, U.S. It is a historically important genus with a convoluted taxonomy that has been all but abandoned by modern dinosaur paleontologists.
Saurolophus is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 68 million years ago. It is one of the few genera of dinosaurs known from multiple continents. The type species, S. osborni, was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, S. angustirostris, is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky.
Shantungosaurus is a genus of very large saurolophine hadrosaurid dinosaur found in the Late Cretaceous Wangshi Group of the Shandong Peninsula in China, containing a single species, Shantungosaurus giganteus. The stratigraphic interval of Shantungosaurus ranges from the top of the Xingezhuang Formation to the middle of the Hongtuya Formation, middle to late Campanian in age. Shantungosaurus is so far the largest hadrosauroid taxon in the world: the greatest length of its femur is about 1.7 metres (5.6 ft), and the greatest length of its humerus is about 0.97 metres (3.2 ft).
Olorotitan was a genus of lambeosaurine duckbilled dinosaur from the middle or latest Maastrichtian-age Late Cretaceous, whose remains were found in the Udurchukan Formation beds of Kundur, Amur Region, Far Eastern Russia. The type, and only species is Olorotitan arharensis. It was one of the last non-avian dinosaurs and it went extinct during the Cretaceous–Paleogene extinction event.
Amurosaurus is a genus of lambeosaurine hadrosaurid dinosaur found in the latest Cretaceous period of eastern Asia. Like most lambeosaurs, it would have been a primarily bipedal herbivore with a "duckbill" shaped snout and a hollow crest on top of its head, although such a crest has not been found. Fossil bones of adults are rare, but an adult would most likely have been at least 6 metres (20 ft) long. According to Gregory S. Paul, it was about 8 metres (26 ft) long and weighed about 3,000 kilograms (6,600 lb).
Arstanosaurus is a genus of hadrosauroid dinosaur from the Santonian-Campanian-age Upper Cretaceous Bostobe Formation, Kazakhstan. It has had a confusing history, being considered both a hadrosaurid and a ceratopsid, or both at the same time (chimeric).
Pararhabdodon is a genus of tsintaosaurin hadrosaurid dinosaur, from the Maastrichtian-age Upper Cretaceous Tremp Group of Spain. The first remains were discovered from the Sant Romà d’Abella fossil locality and assigned to the genus Rhabdodon, and later named as the distinct species Pararhabdodon isonensis in 1993. Known material includes assorted postcranial remains, mostly vertebrae, as well as maxillae from the skull. Specimens from other sites, including remains from France, a maxilla previously considered the distinct taxon Koutalisaurus kohlerorum, an additional maxilla from another locality, the material assigned to the genera Blasisaurus and Arenysaurus, and the extensive Basturs Poble bonebed have been considered at different times to belong to the species, but all of these assignments have more recently been questioned. It was one of the last non-avian dinosaurs known from the fossil record that went extinct during the Cretaceous-Paleogene extinction event.
Nipponosaurus is a lambeosaurine hadrosaur from sediments of the Yezo Group, Sinegorsk, Sakhalin Island in Russia, part of Japan at the time of naming. The type and only species is N. sachalinensis, known only from a single juvenile specimen discovered in 1934 and named in 1936, by Takumi Nagao, with further material of the same individual found in 1937. Since then, the taxon has been largely ignored, and its validity has been doubted, with synonymy with other Asian hadrosaurs or status as a nomen dubium being suggested. Redescriptions from 2004 and 2017, however, have supported recognition as a distinct species. Dating the only specimen has been difficult, but based on associated mollusc taxa, the species likely lived sometime in the upper Santonian or lower Campanian, around 80 million years ago.
Kerberosaurus was a genus of saurolophine duckbill dinosaur from the late Maastrichtian-age Upper Cretaceous Tsagayan Formation of Blagoveshchensk, Amur Region, Russia. It is based on bonebed material including skull remains indicating that it was related to Saurolophus and Prosaurolophus.
Prosaurolophus is a genus of hadrosaurid dinosaur from the Late Cretaceous of North America. It is known from the remains of at least 25 individuals belonging to two species, including skulls and skeletons, but it remains obscure. Around 9 m (30 ft), its fossils have been found in the late Campanian-age Upper Cretaceous Dinosaur Park Formation in Alberta, and the roughly contemporaneous Two Medicine Formation in Montana, dating to around 75.5-74.0 million years ago. Its most recognizable feature is a small solid crest formed by the nasal bones, sticking up in front of the eyes.
Saurolophinae is a subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. However, the name Hadrosaurinae is based on the genus Hadrosaurus which was found in more recent studies to be more primitive than either lambeosaurines or other traditional "hadrosaurines", like Edmontosaurus and Saurolophus. As a result of this, the name Hadrosaurinae was dropped or restricted to Hadrosaurus alone, and the subfamily comprising the traditional "hadrosaurines" was renamed the Saurolophinae. Recent phylogenetic work by Hai Xing indicates that Hadrosaurus is placed within the monophyletic group containing all non-lambeosaurine hadrosaurids. Under this view, the traditional Hadrosaurinae is resurrected, with the Hadrosauridae being divided into two clades: Hadrosaurinae and Lambeosaurinae.
Saurolophini is a tribe of saurolophine hadrosaurids native to the Americas and Asia. It includes Saurolophus, Augustynolophus, and Prosaurolophus. Kerberosaurus and Kundurosaurus may also be members. Bonapartesaurus, a hadrosaurid from Argentina, also has been identified as a member of this tribe.
Edmontosaurini are a tribe of saurolophine hadrosaur dinosaurs that lived in the Northern Hemisphere during the Late Cretaceous period. It currently contains Edmontosaurus, Shantungosaurus and Laiyangosaurus, and Kamuysaurus. Kerberosaurus and Kundurosaurus from Russia could also be members, though they are more likely saurolophins.
Edmontosaurus regalis is a species of comb-crested hadrosaurid (duck-billed) dinosaur. Fossils of E. regalis have been found in rocks of western North America that date from the late Campanian stage of the Cretaceous Period 73 million years ago.
Sahaliyania is a genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Heilongjiang, China.
Arkharavia is a dubious genus of somphospondylan sauropod, but at least some of the remains probably belong to a hadrosaurid. It lived in what is now Russia, during the Late Cretaceous. It was described in 2010 by Alifanov and Bolotsky. The type species is A. heterocoelica.
Kundurosaurus is an extinct genus of saurolophine hadrosaurid dinosaur known from the Latest Cretaceous of Amur Region, Far Eastern Russia. It contains a single species, Kundurosaurus nagornyi.
Brachylophosaurini is a tribe of saurolophine hadrosaurs with known material being from N. America and potentially Asia. It contains at least four taxa; Acristavus, Brachylophosaurus, Maiasaura, and Probrachylophosaurus. A hadrosaur from the Amur river, Wulagasaurus, might be a member of this tribe, but this is disputed. The group was defined by Terry A. Gates and colleagues in 2011.
Kritosaurini is a tribe of saurolophine hadrosaurid dinosaurs from the Late Cretaceous.
This timeline of hadrosaur research is a chronological listing of events in the history of paleontology focused on the hadrosauroids, a group of herbivorous ornithopod dinosaurs popularly known as the duck-billed dinosaurs. Scientific research on hadrosaurs began in the 1850s, when Joseph Leidy described the genera Thespesius and Trachodon based on scrappy fossils discovered in the western United States. Just two years later he published a description of the much better-preserved remains of an animal from New Jersey that he named Hadrosaurus.
