Hadrosauroidea is a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

or superfamily of

ornithischia Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek s ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s that includes the "duck-billed" dinosaurs, or

hadrosaurid Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which inclu ...

s, 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 ''Probactrosaurus'' (meaning "before ''Bactrosaurus''") is an early herbivorous hadrosauroid iguanodont dinosaur. It lived in China during the Late Cretaceous period. Discovery and species In 1959 and 1960 a Soviet-Chinese expedition uncovered ...

'' and ''

Altirhinus ''Altirhinus'' (; "high snout") is a genus of hadrosauroid ornithopod dinosaur from the Early Cretaceous period of Mongolia. History of discovery All known specimens of ''Altirhinus'' were recovered in 1981 during collaborative expeditions organ ...

'', have traditionally been included in a

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

(unnatural grouping) "

Iguanodontidae Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia. Characterized by their elongated maxillae, they were herbivorous and typically large in size. This family exhibited locomotive dynam ...

". With cladistic analysis, the traditional Iguanodontidae has been largely disbanded, and probably includes only ''Iguanodon'' and perhaps its closest relatives.

Classification

The cladogram below follows an analysis by Andrew McDonald, 2012, and shows the position of Hadrosauroidea within Styracosterna. The cladogram below follows an analysis by Wu Wenhao and Pascal Godefroit (2012). Cladogram after Prieto-Marquez and Norell (2010). A

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis performed by Ramírez-Velasco ''et al.'' (2012) found a large polytomy between all hadrosauroids that are more derived than ''

'' but less derived than

Hadrosauridae Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includ ...

. The exclusion of ''

Claosaurus ''Claosaurus'' ( ; Greek κλάω, ''klao'' meaning 'broken' and , ''sauros'' meaning 'lizard'; "broken lizard", referring to the odd position of the fossils when discovered) is a genus of hadrosauroid dinosaur that lived during the Late Cretaceo ...

'', ''

Jeyawati ''Jeyawati'' (meaning "grinding mouth" in the Zuni language) is a genus of hadrosauroid dinosaur which lived during the Turonian stage of the Late Cretaceous. The type species, ''J. rugoculus'', was described in 2010, based on fossils recovered ...

'', ''

Levnesovia ''Levnesovia'' is a genus of hadrosauroid dinosaur from the Late Cretaceous Bissekty Formation of Uzbekistan. It was related to ''Bactrosaurus''. The type species is ''L. transoxiana''. The genus name honours the late Russian paleontologist Lev ...

'', ''

Nanyangosaurus ''Nanyangosaurus'' is a genus of herbivorous ornithischian dinosaur belonging to Hadrosauroidea that lived in the Late Cretaceous of present-day Henan Province, China. In 1994 the remains of ''Nanyangosaurus'' were found near the village of Hou ...

'', ''

Shuangmiaosaurus ''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.Carpenter, K. and Ishida, Y. (2010).Early and “Middle” Cretaceous Iguano ...

'' and '' Telmatosaurus'' from the analysis resulted in a more resolved topology.

References

{{Taxonbar, from=Q1032465 Early Cretaceous first appearances Maastrichtian extinctions

Classification

See also

References