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.
Hypsilophodon is a neornithischian dinosaur genus from the Early Cretaceous period of England and Romania. It has traditionally been considered an early member of the group Ornithopoda, but recent research has put this into question.
Ornithopoda is a clade of ornithischian dinosaurs, called ornithopods, that started out as small, bipedal running grazers and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, dominating the North American land. Their major evolutionary advantage was the progressive development of a chewing apparatus that became the most sophisticated ever developed by a non-avian dinosaur, rivaling that of modern mammals such as the domestic cow. They reached their apex of diversity and ecological dominance in the hadrosaurids, before they were wiped out by the Cretaceous–Paleogene extinction event along with all other non-avian dinosaurs. Members are known from all seven continents, though they are generally rare in the Southern Hemisphere.
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'.
Cryptosaurus is a dubious genus of dinosaur known from a partial femur from the Late Jurassic of England. The sole species is Cryptosaurus eumerus.
Callovosaurus is a genus of iguanodontian dinosaur known from most of a left thigh bone discovered in Middle Jurassic-age rocks of England. At times, it has been considered dubious or a valid genus of basal iguanodontian, perhaps a dryosaurid.
Mochlodon is a genus of rhabdodontid dinosaurs from the Late Cretaceous of Austria and Hungary. It lived during the Late Cretaceous and two species are known: M. suessi and M. vorosi.
Oligosaurus is a genus of iguanodont dinosaurs from the Late Cretaceous Grünbach Formation of Austria.
Ornithopsis is a genus of sauropod dinosaur, from the Early Cretaceous of England. The type species, which is the only species seen as valid today, is O. hulkei, which is only known from fragmentary remains, and has been regarded by many authors as dubious.
Theiophytalia is a genus of herbivorous iguanodontian dinosaur from the lower Cretaceous period of Colorado, USA. It contains a single species, T. kerri.
Mantellisaurus is a genus of iguanodontian dinosaur that lived in the Barremian and early Aptian ages of the Early Cretaceous Period of Europe. Its remains are known from Belgium (Bernissart), England, Spain and Germany. The type and only species is M. atherfieldensis. Formerly known as Iguanodon atherfieldensis, the new genus Mantellisaurus was erected for the species by Gregory Paul in 2007. According to Paul, Mantellisaurus was more lightly built than Iguanodon and more closely related to Ouranosaurus, making Iguanodon in its traditional sense paraphyletic. It is known from many complete and almost complete skeletons. The genus name honours Gideon Mantell, the discoverer of Iguanodon.
Dryosauridae was a family of primitive iguanodonts, first proposed by Milner & Norman in 1984. They are known from Middle Jurassic to Early Cretaceous rocks of Africa, Europe, and North America.
Dakotadon is a genus of iguanodont dinosaur from the Barremian-age Lower Cretaceous Lakota Formation of South Dakota, USA, known from a partial skull. It was first described in 1989 as Iguanodon lakotaensis, by David B. Weishampel and Philip R. Bjork. Its assignment has been controversial. Some researchers suggest that "I." lakotaensis was more basal than I. bernissartensis, and related to Theiophytalia, but David Norman has suggested that it was a synonym of I. bernissartensis. Gregory S. Paul, working on a revision of iguanodont species, gave "I." lakotaensis its own genus (Dakotadon) in 2008. He measured its length at 6 metres (20 ft) and body mass at 1 metric ton.
Owenodon is a genus of iguanodontian dinosaur known from a partial lower jaw discovered in Early Cretaceous-age rocks of Durlston Bay, Dorset, United Kingdom, and possibly also Romania and Spain. The specimen, NHM R2998, comes from the Purbeck Limestone, dating to the middle Berriasian stage. It was first described by Richard Owen, who in 1874 assigned it to Iguanodon as the type specimen of the new species I. hoggii, the specific name honouring naturalist A.J. Hogg who had originally collected the fossil in 1860. The bone was damaged during initial preparation but was freed from the surrounding rock matrix by an acid bath between 1975 and 1977. David Norman and Paul Barrett subsequently transferred the species to Camptosaurus in 2002, but this was challenged, and in 2009 Peter Galton assigned the species to the new genus Owenodon, meaning "Owen's tooth", named after Sir Richard Owen. Galton interpreted the genus as an iguanodontoid more derived than Camptosaurus but less derived than Lurdusaurus.
Hypselospinus is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon by Richard Lydekker in 1889, the specific name honouring William Henry Fitton.
Barilium is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon by Richard Lydekker in 1888, the specific epithet honouring the discoverer Charles Dawson.
Hippodraco is a genus of iguanodontian ornithopod dinosaur from the Early Cretaceous Cedar Mountain Formation of Utah, United States. The genus contains a single species, H. scutodens, known from a partial skeleton belonging to an immature individual.
Duriatitan is a genus of titanosauriform sauropod dinosaur that lived in the Late Jurassic in what is now England. The holotype specimen of Duriatitan, BMNH 44635, is a partial left upper arm bone which was found by R.I. Smith near Sandsfoot in the lower Kimmeridge Clay from Dorset. The type species, D. humerocristatus, was described in 1874 by John Hulke as a species of Cetiosaurus and was noted as being similar to that of Gigantosaurus. The specific name refers to the deltopectoral crest, crista, on the upper arm bone, humerus. The specimen was assigned to its own genus by Paul M. Barrett, Roger B.J. Benson and Paul Upchurch in 2010. The generic name is derived from the Latin name for Dorset, Duria, and Greek Titan. Thomas Holtz estimated its length at 25 meters (82 ft).
Uteodon is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the late Jurassic period in what is now Uintah County, Utah. It is known from the middle of the Brushy Basin Member, Morrison Formation. The genus was named by Andrew T. McDonald in 2011 and the type species is U. aphanoecetes.
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.
