''Chunerpeton tianyiensis'' is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...

from the Late

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

Daohugou Beds The Haifanggou Formation (), also known as the Jiulongshan Formation (), is a fossil-bearing rock deposit located near Daohugou () village of Ningcheng County, in Inner Mongolia, northeastern China. The formation consists of coarse conglomerat ...

in Ningcheng County, Nei Mongol (Inner Mongolia), China. It is the only species classified under the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Chunerpeton''. It was a small animal measuring 18 cm in length. It was

neotenic Neoteny (), also called juvenilization,Montagu, A. (1989). Growing Young. Bergin & Garvey: CT. is the delaying or slowing of the physiological, or somatic, development of an organism, typically an animal. Neoteny is found in modern humans compa ...

, with the retention of

external gills External gills are the gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside the pharynx and covered by gill slits, as they are in most fishes. Instead, the respiratory organs are set on a fril ...

into adulthood. In the original description it was placed in

Cryptobranchidae The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two li ...

, which contains modern giant salamanders. A redescription published in 2020 found it to be a

stem-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

caudatan outside the crown group of modern salamanders. A 2021 study found it to be a member of

Cryptobranchoidea The Cryptobranchoidea are a suborder of salamanders found in Asia, European Russia, and the United States. They are known as primitive salamanders, in contrast to Salamandroidea, the advanced salamanders. It has two living subdivisions, Cryptobra ...

outside of Cryptobranchidae. It lived with other primitive salamanders, e.g. ''

Jeholotriton paradoxus ''Jeholotriton'' is a genus of primitive salamander from the Daohugou Beds (possibly dating to the late Jurassic period) near Daohugou village of Inner Mongolia, China. Wang Yuan from the Institute of Vertebrate Paleontology and Paleoanthropo ...

'' Wang 2000, ''

Liaoxitriton daohugouensis ''Liaoxitriton'' is an extinct genus of prehistoric cryptobranchoid salamanders from the Early Cretaceous of China. It contains one species, ''L. zhongjiani'', from the Aptian aged Yixian Formation. A second species, ''L. daohugouensis'' fro ...

'' Wang 2004, and ''

Pangerpeton sinensis ''Pangerpeton'' is an extinct genus of salamanders. Its monotypic species is ''Pangerpeton sinensis''. ''Pangerpeton'' is a metamorphosed, primitive salamander from the Late Jurassic Daohugou fossil bed near Wubaiding Village of Lingyuan City, ...

'' Wang & Evans 2006 of the same age.

References

Further reading