Andrias matthewi

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
Domain:	Eukaryota
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]

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]

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]

References

1. Holman, J.A. (2006). Fossil Salamanders of North America. Bloomington, IN: Indiana University Press. pp. 71–73. ISBN   0-253-34732-7.
2. Cook, H.J. (1917). "First recorded amphibian from the Tertiary of Nebraska". Bulletin of the Geological Society of America. 28: 213.
3. Tihen, J.A.; Chantell, C.J. (1963). "Urodele remains from the Valentine Formation of Nebraska" . Copeia. 1963 (3): 505-510. doi:10.2307/1441470. JSTOR   1441470.
4. Holman, J.A. (1976). "The herpetofauna of the lower Valentine Formation, north-central Nebraska" . Herpetologica. 32 (3): 262–268. JSTOR   3891452.
5. Naylor, B.G. (1981). "Cryptobranchid salamanders from the Paleocene and Miocene of Saskatchewan" . Copeia. 1981 (1): 76–86. doi:10.2307/1444042. JSTOR   1444042.
6. Skinner, M.F.; Skinner, S.M.; Gooris, R.J. (1977). "Stratigraphy and biostratigraphy of late Cenozoic deposits in central Sioux County, western Nebraska". Bulletin of the American Museum of Natural History. 158 (5): 263-370. hdl:2246/1233.
7. Meszoely, C. (1966). "North American fossil cryptobranchid salamanders" . The American Midland Naturalist. 75 (2): 495–515. doi:10.2307/2423407. JSTOR   2423407.
8. Turvey, S.T.; Marr, M.M.; Barnes, I.; Brace, S.; Tapley, B.; Murphy, R.W.; Zhao, E.; Cunningham, A.A. (2019). "Historical museum collections clarify the evolutionary history of cryptic species radiation in the world's largest amphibians". Ecology and Evolution. 9 (18): 10070–10084. Bibcode:2019EcoEv...910070T. doi: 10.1002/ece3.5257 . PMC   6787787 . PMID   31624538.