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.
Claosaurus is a genus of hadrosauroid dinosaur that lived during the Late Cretaceous Period (Santonian-Campanian).
Hypacrosaurus was a genus of duckbill dinosaur similar in appearance to Corythosaurus. Like Corythosaurus, it had a tall, hollow rounded crest, although not as large and straight. It is known from the remains of two species that spanned 75 to 67 million years ago, in the Late Cretaceous of Alberta, Canada, and Montana, United States, and is the latest hollow-crested duckbill known from good remains in North America. It was an obscure genus until the discovery in the 1990s of nests, eggs, and hatchlings belonging to H. stebingeri.
Jaxartosaurus is a genus of hadrosaurid dinosaur similar to Corythosaurus which lived during the Late Cretaceous. Its fossils were found in Kazakhstan.
Parksosaurus is a genus of neornithischian dinosaur from the early Maastrichtian-age Upper Cretaceous Horseshoe Canyon Formation of Alberta, Canada. It is based on most of a partially articulated skeleton and partial skull, showing it to have been a small, bipedal, herbivorous dinosaur. It is one of the few described non-hadrosaurid ornithopods from the end of the Cretaceous in North America, existing around 70 million years ago.
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).
Barsboldia is a genus of large hadrosaurid dinosaur from the early Maastrichtian Nemegt Formation of Ömnogöv', Mongolia. It is known from a partial vertebral column, partial pelvis, and some ribs.
Mandschurosaurus is an extinct genus of hadrosaurids based on material from the Late Cretaceous of China and possibly also the Early Cretaceous of Laos. It was the first dinosaur genus named from China.
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.
Microhadrosaurus is a genus of hadrosaurid dinosaur from the Campanian or Maastrichtian-age Upper Cretaceous Yuanpu Formation of Guangdong, China. Although its name identifies it as a small hadrosaur, it is based on juvenile remains, and the size of the adult hadrosaur is unknown.
Orthomerus is a genus of dubious hadrosaurid dinosaur from the Late Cretaceous of the Netherlands. It is today an obscure genus, but in the past was conflated with the much better known Telmatosaurus.
Cedrorestes is a genus of iguanodontian dinosaur from the Early Cretaceous of Utah. It is based on an incomplete skeleton which was found in the Valanginian-age Yellow Cat Member of the Cedar Mountain Formation.
Halszka Osmólska was a Polish paleontologist who had specialized in Mongolian dinosaurs.
Wulagasaurus is a genus of saurolophine hadrosaurid dinosaur from the Late Cretaceous of Heilongjiang, China.
Sahaliyania is a genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Heilongjiang, China.
The Kakanaut Formation is a geological formation in Siberia, whose strata date back to the Late Cretaceous (Maastrichtian). Dinosaur remains are among the fossils that have been recovered from the formation. The flora of the formation is relictual, containing some of the youngest remains of the extinct plant orders Bennettitales and Czekanowskiales.
The Murtoi Formation is a geologic formation in vicinity of Lake Gusinoye in Russia. It was deposited in the late Barremian to the mid Aptian of the Early Cretaceous.
The Ialovachsk or Yalovach Formation is a geologic formation in Kyrgyzstan, Tajikistan and Uzbekistan dating to the Santonian age of the Cretaceous period.
Kazaklambia is an extinct genus of herbivorous lambeosaurine dinosaur known from the Late Cretaceous Dabrazinskaya Svita of southern Kazakhstan. It contains a single species, Kazaklambia convincens.
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.
