''Bayannurosaurus'' is a non-hadrosauriform

ankylopollexia 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 wo ...

ornithopod 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 worl ...

described in 2018 by Xu Xing. It lived during the early

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ag ...

period, being found in the

Bayin-Gobi Formation The Bayin-Gobi Formation () (also known as Bayan Gobi, or Bayingebi Formation) is a geological formation in Inner Mongolia, north China, whose strata date back to Albian of the Early Cretaceous period. Dinosaur remains are among the fossils that h ...

of China. The genus includes the type species ''Bayannurosaurus perfectus''. 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 of ''Bayannurosaurus'' indicates that it is more derived than ''

Hypselospinus ''Hypselospinus'' is a genus of iguanodontian dinosaur which was first described as a species of '' Iguanodon'' (''I. fittoni'') by Richard Lydekker in 1889, the specific name honouring William Henry Fitton. History In May 2010 the fossils c ...

'', yet less derived than ''

Ouranosaurus ''Ouranosaurus'' is a genus of herbivorous basal hadrosauriform dinosaur that lived during the Aptian stage of the Early Cretaceous of modern-day Niger and Cameroon. ''Ouranosaurus'' measured about long. Two rather complete fossils were found i ...

'' and just outside of the

Hadrosauriformes 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 wo ...

. It had a skull length of 80cm, making it a mid-sized

iguanodontian Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include ''Camptosaurus'', ''Dryosaurus'', ''Iguanodon'', '' Tenontosaurus'', and the hadrosaurids or "duck-b ...

. By comparison, ''

'' had a 67cm long skull, and a length of 7 to 8.3 meters. Though inexact, if this is used as a comparison to scale, ''Bayannurosaurus'' would be 8.3 to 10 meters long. The genus name ''Bayannurosaurus'' comes from

Bayannur Bayannur or Bayannao'er (; mn, ''Bayannaɣur qota'', Mongolian Cyrillic Баяннуур хот) is a prefecture-level city in western Inner Mongolia, People's Republic of China. Until 1 December 2003, the area was called Bayannur League. ...

, the area where it was found, while the species name ''perfectus'' comes from the "perfect" preservation of the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

specimen.

References

Iguanodonts Early Cretaceous dinosaurs of Asia Fossil taxa described in 2018 Cretaceous China Ornithischian genera {{ornithischian-stub

See also

References