Changmiania

Changmiania (from the Chinese "changmian", meaning "eternal sleep") is a genus of basal ornithopod dinosaur that lived in what is now China during the Early Cretaceous. It contains a single species, Changmiania liaoningensis.

Changmiania
Temporal range: Early Cretaceous, Barremian
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: †Ornithischia
Suborder: †Ornithopoda
Genus: †Changmiania
Yang et al., 2020
Species:
†C. liaoningensis
Binomial name
†Changmiania liaoningensis
Yang et al., 2020

Discovery and naming

The taxon is represented by two near-complete articulated skeletons: the holotype specimen, PMOL AD00114; and a referred specimen, PMOL LFV022. These remains were discovered in the Barremian age, 123.2 million years old, Lujiatun Beds of the Yixian Formation by local farmers and partially prepared. They were acquired by the Paleontological Museum of Liaoning at Shenyang, which completed the preparation. No indications were found that the fossils had been tampered with by fossil traders. The perfect life-like positions of these specimens suggest that they were buried alive, possibly in their own burrows.[1]

In 2020, the type species Changmiania liaoningensis was named and described by Yang Yuqing, Wu Wenhao, Paul-Emile Dieudonné and Pascal Godefroit. The generic name is derived from 長眠 (cháng mián), "eternal sleep" in Chinese, referring to the possible sleep position the fossils were found in. The specific name refers to the provenance from Liaoning.[1]

Description

Size comparison

The holotype specimen has a preserved length of 117 centimetres.[1]

The describing authors established some distinguishing traits. Some of these were autapomorphies, unique derived characters. The frontal bones are elongated, over four times longer than wide. The parietals do not share a midline crest. The front branch of the squamosal bone is straight and elongated. On the upper rear corner of the squamosal a distinctive boss is present. The lower edge of the dentary is convex but the edge of the angular bone is strongly concave, resulting in a sinuous profile for the lower jaw as a whole. The neural spines of the sacral vertebrae are fused into a continuous elongated plate. Both the lower and upper end of the shoulder blade is asymmetrically expanded. The paired ilia are upwards and inwards inclined, covering the sacrum in top view. The upper part of the calfbone is as robust as that of the shinbone.[1]

Phylogeny

In their phylogenetic analysis, Yang et al. (2020) recovered Chiangmiania as the basalmost ornithopod. The cladogram below follows their results:[1]

Neornithischia
 

Agilisaurus louderbacki

 
 
 

Hexinlusaurus multidens

 
Cerapoda
 
 

Kulindadromeus zabaikalicus

 
 

Marginocephalia

 
 
Ornithopoda
 

Changmiania liaoningensis

 
 
Orodrominae
 

Zephyrosaurus schaffi

 
 

Orodromeus makelai

 
 
 

Yueosaurus tiantaiensis

 
 

Koreanosaurus boseongensis

 
 
 
 
Jeholosaurinae
 

Haya griva

 
 
 

Jeholosaurus shangyuanensis

 
 

Changchunsaurus parvus

 
 
 
 
 
 

Yandusaurus hongheensis

 
 

Nanosaurus agilis

 
 
Clypeodonta
Parksosaurinae
 

Hypsilophodon foxii

 
 
 

Parksosaurus warreni

 
 

Gasparinisaura cincosaltensis

 
 
 
 
 
 

Thescelosaurus assiniboiensis

 
 

Thescelosaurus neglectus

 
 
 

Iguanodontia

 
 
 
 
 
 
 
 
 
 

References

  1. Yang, Y.; Wu, W.; Dieudonné, P.; Godefroit, P. (2020). "A new basal ornithopod dinosaur from the Lower Cretaceous of China". PeerJ. 8: e9832. doi:10.7717/peerj.9832.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.