Andrias matthewi

Andrias matthewi, or Matthew's giant salamander,^[4] is an extinct species of giant salamander from the Miocene of North America. It belongs to the genus Andrias, which contains the living Asian giant salamanders. It is the largest salamander known to have ever existed, with a maximum estimated length of 2.3 m (7 ft 7 in).^[5] Its fossils have been found in Nebraska, Colorado, and Saskatchewan.^[1]

Andrias matthewi Temporal range: Arikareean–Barstovian PreꞒ Ꞓ O S D C P T J K Pg N [1]
Size comparison between a human and A. matthewi
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Urodela
Family:	Cryptobranchidae
Genus:	Andrias
Species:	†A. matthewi
Binomial name
†Andrias matthewi (Cook, 1917)[2]
Synonyms
Plicagnathus matthewi Cook, 1917 Cryptobranchus matthewi (Cook, 1917) Cryptobranchus mccalli Tihen & Chantell, 1963[3]

Taxonomy

In 1917, Harold Cook named the new genus and species Plicagnathus matthewi for a dentary from Nebraska, specifically from the unit known as the "lower Snake Creek beds",^[2] which was later renamed as the Olcott Formation.^[6] The species was named in honor of William Diller Matthew, who first identified the specimen.^[2] In 1963, Joseph Tihen and Charles Chantell named the new species Cryptobranchus mccalli for two maxillae from the Valentine Formation of Nebraska.^[3] Charles Meszoely synonymized C. mccalli with P. matthewi and Plicagnathus with Andrias in 1966, leading to the current name Andrias matthewi.^[7] Bruce Naylor synonymized Andrias with Cryptobranchus in 1981, resulting in the combination Cryptobranchus matthewi,^[5] but this was not accepted by subsequent authors.^[1]

Size

Cook estimated a length of 1.52 m (5 ft 0 in) based on the holotype dentary.^[2] Meszoely estimated lengths of 1.5 m (4 ft 11 in) and 1.8 m (5 ft 11 in) from a referred maxilla and dentary, respectively, from the Marsland Formation of Nebraska.^[7] Naylor estimated a length of 2.3 m (7 ft 7 in) using two vertebrae from the Wood Mountain Formation of Saskatchewan.^[5] In comparison, the largest living salamander, the South China giant salamander (Andrias sligoi), reaches lengths of 1.75 m (5 ft 9 in).^[8]