''Andrias matthewi'', or Matthew's giant salamander, 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 ...

giant salamander 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 ...

from the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

of North America. It belongs to the genus ''

Andrias ''Andrias'' is a genus of giant salamanders. It includes the largest salamanders in the world, with ''A. japonicus'' reaching a length of , and ''A. sligoi'' reaching . While extant species are only known from East Asia, several extinct species i ...

'', which contains the living Asian giant salamanders. It is the largest salamander to have ever existed, with a maximum estimated length of . Its fossils have been found in

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the sout ...

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

, and

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

Taxonomy

In 1917, Harold Cook named the new genus and species ''Plicagnathus matthewi'' for a

dentary In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

from the "lower Snake Creek beds" of Nebraska. The species was named in honor of

William Diller Matthew William Diller Matthew FRS (February 19, 1871 – September 24, 1930) was a vertebrate paleontologist who worked primarily on mammal fossils, although he also published a few early papers on mineralogy, petrological geology, one on botany, one on ...

, who first identified the specimen. In 1963, Joseph Tihen and Charles Chantell named the new species '' Cryptobranchus mccalli'' for two maxillae from the Valentine Formation of Nebraska. Charles Meszoely synonymized ''C. mccalli'' with ''P. matthewi'' and ''Plicagnathus'' with ''Andrias'' in 1966, leading to the current name ''Andrias matthewi''. Bruce Naylor synonymized ''Andrias'' with ''Cryptobranchus'' in 1981, resulting in the combination ''Cryptobranchus matthewi'', but this was not accepted by subsequent authors.

Size

Cook estimated a length of based on 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 sever ...

dentary. Meszoely estimated lengths of and from a referred maxilla and dentary, respectively, from the Marsland Formation of Nebraska. Naylor estimated a length of using two

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

from the

Wood Mountain Formation The Wood Mountain Formation is a geologic formation in Saskatchewan. It preserves fossils dating back to the Neogene period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, ent ...

of Saskatchewan. In comparison, the largest living salamander, the

South China giant salamander The South China giant salamander (''Andrias sligoi'') may be the largest species of salamander and the largest amphibian in the world. It is Endemism, endemic to southern China, mainly in the Pearl River (China), Pearl River basin south of the Na ...

(''Andrias sligoi''), reaches lengths of .

Notes

References

{{Taxonbar, from=Q113647995 Cryptobranchidae Amphibians described in 1917