Hadrosauroidea

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

Hadrosauroids Temporal range: Early-Late Cretaceous,
Probactrosaurus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Neornithischia
Clade:	†Ornithopoda
Clade:	†Hadrosauriformes
Superfamily:	†Hadrosauroidea Cope, 1869
Type species
†Hadrosaurus foulkii Leidy, 1858
Subgroups
†Altirhinus †Batyrosaurus †Bolong? †Choyrodon †Datonglong †Equijubus †Gongpoquansaurus †Koshisaurus †Jinzhousaurus? †Mantellisaurus? †Ouranosaurus? †Penelopognathus †Portellsaurus †Probactrosaurus †Qianjiangsaurus †Siamodon †Sirindhorna †Xuwulong †Zuoyunlong †Hadrosauromorpha
Synonyms
Trachodontoidea Lydekker, 1888 Hadrosauria Huene, 1956

Classification

Hadrosauroidea was given a formal phylogenetic definition in the PhyloCode by Daniel Madzia and colleagues in 2021 as "the largest clade containing Hadrosaurus foulkii, but not Iguanodon bernissartensis". The cladogram below follows an analysis by Andrew McDonald, 2012, and shows the position of Hadrosauroidea within Styracosterna:

Styracosterna	Uteodon aphanoecetes Hippodraco scutodens Theiophytalia kerri Iguanacolossus fortis Lanzhousaurus magnidens Kukufeldia tilgatensis Barilium dawsoni Hadrosauriformes Iguanodon bernissartensis Hadrosauroidea Mantellisaurus atherfieldensis Other hadrosauroids

The cladogram below follows an analysis by Wu Wenhao and Pascal Godefroit (2012):

Hadrosauriformes	Iguanodontidae  Iguanodon Ouranosaurus Mantellisaurus  Hadrosauroidea  Bolong Equijubus Jinzhousaurus Altirhinus Batyrosaurus Probactrosaurus Eolambia Protohadros Bactrosaurus Levnesovia Shuangmiaosaurus Tethyshadros Telmatosaurus Hadrosauridae

Cladogram after Prieto-Marquez and Norell (2010):

Hadrosauroidea	Jinzhousaurus Penelopognathus Equijubus Probactrosaurus Eolambia Protohadros Tanius Bactrosaurus Gilmoreosaurus Telmatosaurus Shuangmiaosaurus Nanyangosaurus Lophorhothon Hadrosauridae

A phylogenetic analysis performed by Ramírez-Velasco et al. (2012) found a large polytomy between all hadrosauroids that are more derived than Probactrosaurus but less derived than Hadrosauridae. The exclusion of Claosaurus, Jeyawati, Levnesovia, Nanyangosaurus, Shuangmiaosaurus and Telmatosaurus from the analysis resulted in a more resolved topology:

Hadrosauroidea	Jinzhousaurus yangi Fukuisaurus tetoriensis Penelopognathus weishampeli Equijubus normani Probactrosaurus gobiensis Eolambia caroljonesa Protohadros byrdi Tanius sinensis Bactrosaurus johnsoni Glishades ericksoni Gilmoreosaurus mongoliensis Huehuecanauhtlus tiquichensis Jintasaurus meniscus Tethyshadros insularis Hadrosauridae

See also

• Timeline of hadrosaur research