Iguanodon, named in 1825, is a genus of iguanodontian dinosaur. While many species found worldwide have been classified in the genus Iguanodon, dating from the Late Jurassic to Early Cretaceous, taxonomic revision in the early 21st century has defined Iguanodon to be based on one well-substantiated species: I. bernissartensis, which lived during the Barremian to early Aptian ages of the Early Cretaceous in Belgium, Germany, England, and Spain, between about 126 and 122 million years ago. Iguanodon was a large, bulky herbivore, measuring up to 9–11 metres (30–36 ft) in length and 4.5 metric tons in body mass. Distinctive features include large thumb spikes, which were possibly used for defense against predators, combined with long prehensile fifth fingers able to forage for food.
Altirhinus is a genus of hadrosauroid ornithopod dinosaur from the Early Cretaceous period of Mongolia.
Eolambia is a genus of herbivorous hadrosauroid dinosaur from the early Late Cretaceous of the United States. It contains a single species, E. caroljonesa, named by paleontologist James Kirkland in 1998. The type specimen of Eolambia was discovered by Carole and Ramal Jones in 1993; the species name honors Carole. Since then, hundreds of bones have been discovered from both adults and juveniles, representing nearly every element of the skeleton. All of the specimens have thus far been found in Emery County, Utah, in a layer of rock known as the Mussentuchit Member of the Cedar Mountain Formation.
Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia.
Tanius is a genus of hadrosauroid dinosaur. It lived in the Late Cretaceous of China. The type species, named and described in 1929 by Carl Wiman, is Tanius sinensis. The generic name honours the Chinese paleontologist Tan Xichou. The specific epithet refers to China. In 2010 Gregory S. Paul estimated the length of Tanius at 7 metres (23 ft) and its weight at 2 metric tons.
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.
Equijubus, is a genus of herbivorous hadrosauroid dinosaur from the Early Cretaceous of northwestern China.
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.
Nipponosaurus is a lambeosaurine hadrosaur from sediments of the Yezo Group, in Sinegorsk on the island of Sakhalin, which was part of Japan at the time of the species' classification. 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.
Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or Hadrosauridae, and all dinosaurs more closely related to them than to Iguanodon. Their remains have been recovered in Asia, Europe, Africa and the Americas. Many primitive hadrosauroids, such as the Asian Probactrosaurus and Altirhinus, have traditionally been included in a paraphyletic "Iguanodontidae". With cladistic analysis, the traditional Iguanodontidae has been largely disbanded, and probably includes only Iguanodon and perhaps its closest relatives.
Shuangmiaosaurus is a genus of herbivorous ornithischian dinosaur which lived during the late Albian age of the Early Cretaceous Period, about 100 million years ago. It was an iguanodont euornithopod which lived in China.
Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word, “ankylos”, mistakenly taken to mean stiff, fused, and the Latin word, “pollex”, meaning thumb. Originally described in 1986 by Sereno, a most likely synapomorphic feature of a conical thumb spine defines the clade.
Willinakaqe is a dubious genus of saurolophine hadrosaurid dinosaur described based on fossils from the late Cretaceous of the Río Negro Province of southern Argentina.
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.
Gongpoquansaurus is an extinct genus of basal hadrosauroid dinosaur that was not formally named until 2014, while the name was a nomen nudum for many years previously. It is known from IVPP V.11333, a partial skull and postcranial skeleton. It was collected in 1992 at locality IVPP 9208–21, from the Albian Zhonggou Formation, in Mazongshan, Gansu Province, China. The specimen was first described and named by Lü Junchang in 1997 as the third species of Probactrosaurus, Probactrosaurus mazongshanensis. Following its description, several studies found it to be less derived than the type species of Probactrosaurus in relation to Hadrosauridae. Therefore, "Gongpoquansaurus" had been suggested, yet informally, as a replacement generic name. In 2014, the species was formally redescribed, and the describers erected Gongpoquansaurus.
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.
Hadrosauromorpha is a clade of iguanodontian ornithopods, defined in 2014 by David B. Norman to divide Hadrosauroidea into the basal taxa with compressed manual bones and a pollex, and the derived taxa that lack them. The clade is defined as all the taxa closer to Edmontosaurus regalis than Probactrosaurus gobiensis. This results in different taxon inclusion depending on the analysis.
Gobihadros is a genus of basal hadrosauroid dinosaur that lived in Asia during the Late Cretaceous period in what is now the Bayan Shireh Formation (Cenomanian-Santonian). It contains only the type species Gobihadros mongoliensis. It has an estimated length of 7.5 m (25 ft).
The Miaogou Formation is a geological formation in Inner Mongolia, north China. While its absolute age is uncertain, it has been estimated to represent Early Cretaceous sediments based on the faunal composition. Dinosaur remains are among the fossils that have been recovered from the formation.
