Aralosaurus was a genus of hadrosaurid dinosaur that lived during the Late Cretaceous in what is now Kazakhstan. It is known only by a posterior half of a skull and some post-cranial bones found in the Bostobe Formation in rocks dated from the Upper Santonian-Lower Campanian boundary, at about 83.6 Ma. Only one species is known, Aralosaurus tuberiferus, described by Anatoly Konstantinovich Rozhdestvensky in 1968. The genus name means Aral Sea lizard, because it was found to the northeast of the Aral Sea. The specific epithet tuberiferus means bearing a tuber because the posterior part of the nasal bone rises sharply in front of the orbits like an outgrowth. Aralosaurus was originally reconstituted with a nasal arch similar to that of North American Kritosaurus. For many years, Aralosaurus was thus placed in the clade of the Hadrosaurinae. This classification was invalidated in 2004, following the re-examination of the skull of the animal which allowed to identify in Aralosaurus many typical characters of Lambeosaurinae. In particular, this study revealed that Aralosaurus had a hollow bony structure located far in front of the orbits, which communicated with the respiratory tract. This structure being broken at its base, its shape and size remains undetermined. More recently, Aralosaurus has been identified as the most basal Lambeosaurinae, and placed with its close relative Canardia from the upper Maastrichtian of France in the new clade of Aralosaurini.
Olorotitan was a monotypic genus of lambeosaurine duck-billed dinosaur, containing a single species, Olorotitan arharensis. It was among the last surviving non-avian dinosaurs to go extinct during the Cretaceous–Paleogene extinction event, having lived from the middle to late Maastrichtian-age of the Late Cretaceous era. The remains were found in the Udurchukan Formation beds of Kundur, Arkharinsky District, Amur Oblast, Eastern Russia, in the vicinity of the Amur River.
Amurosaurus is a genus of lambeosaurine hadrosaurid dinosaur found in the latest Cretaceous period of eastern Asia. 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).
Anasazisaurus is a genus of saurolophine hadrosaurid ("duckbill") ornithopod dinosaur that lived about 74 million years ago, in the Late Cretaceous Period. It was found in the Farmington Member of the Kirtland Formation, in the San Juan Basin of New Mexico, United States. Only a partial skull has been found to date. It was first described as a specimen of Kritosaurus by Jack Horner, and has been intertwined with Kritosaurus since its description. It is known for its short nasal crest, which stuck out above and between its eyes for a short distance.
Charonosaurus is a genus of dinosaur whose fossils were discovered by Godefroit, Zan & Jin in 2000, on the south bank of the Amur River, dividing China from Russia. It is monotypic, consisting of the species C. jiayinensis.
Nodocephalosaurus is a monospecific genus of ankylosaurid dinosaur from New Mexico that lived during the Late Cretaceous in what is now the De-na-zin member of the Kirtland Formation. The type and only species, Nodocephalosaurus kirtlandensis, is known only from a partial skull. It was named in 1999 by Robert M. Sullivan. Nodocephalosaurus has an estimated length of 4.5 metres and weight of 1.5 tonnes. It is closely related and shares similar cranial anatomy to Akainacephalus.
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.
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.
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 Udurchukan Formation is a geological formation located in Amur Region, Far East Russia. Based on palynomorphs such as Wodehouseia spinata, the Udurchukan is considered of Maastrichtian age of the Late Cretaceous, during the Cretaceous Period.
Arkharavia is a dubious genus of somphospondylan sauropod, but at least some of the remains probably belong to a hadrosaurid. It was discovered in the Udurchukan Formation in Russia and lived during the Late Cretaceous. It was described in 2010 by Alifanov and Bolotsky and the type species is A. heterocoelica.
Batyrosaurus is an extinct genus of herbivorous basal hadrosauroid dinosaur known from the Late Cretaceous Bostobe Formation of central Kazakhstan. It contains a single species, Batyrosaurus rozhdestvenskyi. It is possible that Batyrosaurus represents the same taxon as the doubtful Arstanosaurus akkurganensis as both were found from the same formation.
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.
Bonapartesaurus is an extinct genus of herbivorous ornithopod dinosaur belonging to Hadrosauridae, which lived in the area of modern Argentina during the Campanian and Maastrichtian stages of the Late Cretaceous.
Huallasaurus is an extinct genus of saurolophine hadrosaur from the Late Cretaceous Los Alamitos Formation of Patagonia in Argentina. The type and only species is H. australis. Originally named as a species of Kritosaurus in 1984, it was long considered a synonym of Secernosaurus before being recognized as its own distinct genus in a 2022 study, different from other members of Kritosaurini.
