Eothenomys cachinus Thomas 1921

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Cricetidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 955-1189 : 978

publication ID

https://doi.org/ 10.5281/zenodo.7316535

DOI

https://doi.org/10.5281/zenodo.11356958

persistent identifier

https://treatment.plazi.org/id/5E239F79-12F8-D4AD-6D72-643D8D0296E5

treatment provided by

Guido

scientific name

Eothenomys cachinus Thomas 1921
status

 

Eothenomys cachinus Thomas 1921 View in CoL

Eothenomys cachinus Thomas 1921 View in CoL , J. Bombay Nat. Hist. Soc., 27: 504.

Type Locality: NE Burma, Kachin State, Imaw Bum, 9000 ft (2743 m).

Vernacular Names: Kachin Red-backed Vole.

Synonyms: Eothenomys confinii Hinton 1923 .

Distribution: Montane forest, 2300-3200 m, west of the Salween River Valley in NE Burma ( Thomas, 1921 g, the holotype; Anthony, 1941), and adjacent NW Yunnan (holotype of confinii Hinton, 1923 ); range may extend farther south to extreme W Yunnan and EC Burma.

Discussion: E. melanogaster species group. Described by Thomas (1921 g) as a species but subsequently included either in E. melanogaster ( Hinton, 1923; Ellerman, 1941, 1961; Ellerman and Morrison-Scott, 1951; Corbet, 1978 c; Musser and Carleton, 1993; Pavlinov et al., 1995 a) or E. miletus ( Corbet and Hill, 1992) . Comparisons of Anthony’s (1941) large AMNH sample, obtained at the type locality of cachinus and vicinity, with E. miletus and E. melanogaster proper confirm Thomas’ view that cachinus is a distinctive species. Adult E. cachinus are large-bodied and long-tailed, with soft, long and thick fur, the upperparts bright tawny brown and the underparts gray washed with hues ranging from pale buff to ochraceous (the only species in the E. melanogaster group with such bright venters). They are about the same body size as the large E. miletus , but have longer tails (mean = 50.9 mm, range = 43-61 mm, n = 105) than E. miletus (43.6 mm, 35-48 mm, n = 39) and E. melanogaster (36.1 mm, 31-42 mm, n = 34); no other species in the E. melanogaster group has such a long tail. Compared with E. miletus , cranium of E. cachinus is slightly smaller in length and width dimensions and strikingly much lower in profile (flattened compared with the high, arched and stocky cranium of E. miletus ); M3 has four lingual salient angles (like E. miletus ), but also four labial angles in 95 of 109 specimens (three in E. miletus ). Occlusal pattern consists of a single anterior lamina, two inverted chevron-shaped laminae, and an irregularly-shaped heel, while all other forms have only two anterior laminae and a heel with an angular labial projection. Thomas (1921 g) clearly described the M3 pattern in cachinus , and Hinton (1923) used it to separate cachinus from other forms of melanogaster in his key to Eothenomys .

We synonymize the NW Yunnan confinii with E. cachinus in contrast to its peripatetic association under E. eleusis (G. M. Allen, 1940; Zhang et al., 1997), E. melanogaster ( Corbet and Hill, 1992) , E. mucronatus (Kaneko, 2002) , or E. miletus ( Ye et al., 2002) . Hinton’s (1923) description of the pelage and tail length (59 mm) matches that of E. cachinus , his cranial differences between confinii and miletus precisely distinguish E. cachinus from E. miletus , and confinii too was obtained west of the Salween River Valley adjacent to the region where Anthony (1941) worked. Kaneko (2002) relegated both cachinus and confinii , along with miletus , to E. mucronatus (here considered a junior synonym of E. melanogaster ; see below). Examination of the same specimens studied by Kaneko (2002) supplies no morphological evidence for considering the three taxa as members of a single species. Specimens of E. cachinus (including confinii ) and E. miletus can be consistently separated by cranial conformation and relative tail length (comparing specimens of similar age), as previously indicated.

In NE Burma, Anthony (1941) encountered E. cachinus (identified as E. melanogaster cachinus ) in heavy forest, 2300-3200 m, and found the smaller E. melanogaster (reported as E. m. libonotus ) at lower elevations, 1200-2750, in open habitats (meadows, near cultivation, and shrubby growth along streams). This region of Burma also harbors two endemic murines, Niviventer brahma ( Musser, 1970 b, 1973 a) and an undescribed species of Niviventer (Musser and Lunde, ms). Curiously, Zhang et al. (1997) listed cachinus both as a separate species and as a synonym of E. melanogaster . The specimens that Ellerman (1961) recorded from N Burma are E. melanogaster .

AMNH

American Museum of Natural History

Kingdom

Animalia

Phylum

Chordata

Class

Mammalia

Order

Rodentia

Family

Cricetidae

Genus

Eothenomys

Loc

Eothenomys cachinus Thomas 1921

Wilson, Don E. & Reeder, DeeAnn 2005
2005
Loc

Eothenomys cachinus

Thomas 1921: 504
1921
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