Nephelomys pectoralis
Encyclopedia
Nephelomys pectoralis is a species of rodent
in the genus Nephelomys
of family Cricetidae
. Its type locality is 40 miles (64 km) west of the city of Popayán
, Cauca Department
, Colombia
, at an altitude of 10340 feet (3,151.6 m). American zoologist Joel Asaph Allen
first described it in 1912 on the basis of 112 specimens from several locations in the Cordillera Occidental. He classified it as a species of Oryzomys
, Oryzomys pectoralis, but later subsumed into the species Oryzomys albigularis. When that species was transferred to the new genus Nephelomys
in 2006, N. pectoralis was recognized as a separate species.
N. pectoralis is larger than various other Nephelomys species, but smaller than N. maculiventer
. Its upperparts are yellowish brown, and at the sides there is a distinct yellow line. Younger specimens may have some black hairs interspersed in the fur of the upperparts. The hairs of the underparts are grey at the bases and white at the tips, but those in a region of variable size on the chest are completely white. The underparts become lighter in color with age. The ears are dark brown and mostly naked. The tail is grayish brown and there is scarcely any difference in color between the upper and lower side. The hindfeet are covered with thin pale hairs. Juvenile individuals are dark brown to blackish, with the underparts dark gray in color, except for the well-defined white patch at the chest. In 41 specimens, the total length ranges from 300 to 330 mm (11.8 to 13 in), the head and body length from 136 to 166 mm (5.4 to 6.5 in), the hindfoot length from 33.5 to 38 mm (1.3 to 1.5 in), and the skull length from 34 to 37 mm (1.3 to 1.5 in).
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the genus Nephelomys
Nephelomys
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica...
of family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
. Its type locality is 40 miles (64 km) west of the city of Popayán
Popayán
Popayán is the capital of the Colombian department of Cauca. It is located in southwestern Colombia between Colombia's Western Mountain Range and Central Mountain Range...
, Cauca Department
Cauca Department
Cauca is a Department of Colombia. Located in the south-western part of the country, facing the Pacific Ocean to the west, the Valle del Cauca Department to the north, Tolima Department to the northeast, Huila Department to the east and the Nariño Department to the south, covering a total area of...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, at an altitude of 10340 feet (3,151.6 m). American zoologist Joel Asaph Allen
Joel Asaph Allen
Joel Asaph Allen was an American zoologist and ornithologist, born in Springfield, Massachusetts.He studied at Harvard University under Louis Agassiz...
first described it in 1912 on the basis of 112 specimens from several locations in the Cordillera Occidental. He classified it as a species of Oryzomys
Oryzomys
Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat of the United States and O. couesi of Mexico and Central America—are widespread; the six others have...
, Oryzomys pectoralis, but later subsumed into the species Oryzomys albigularis. When that species was transferred to the new genus Nephelomys
Nephelomys
Nephelomys is a genus of South American oryzomyine rodents found in the Andes from Bolivia to Venezuela, with a westward extension into the mountains of Costa Rica...
in 2006, N. pectoralis was recognized as a separate species.
N. pectoralis is larger than various other Nephelomys species, but smaller than N. maculiventer
Nephelomys maculiventer
Nephelomys maculiventer is a species of rodent in the genus Nephelomys of family Cricetidae. The type locality is in Colombia, at "Sierra El Libano, alt. 6000 ft, Santa Marta District". It was originally described on the basis of 47 specimens, including 34 from Sierra El Libano and 13 from...
. Its upperparts are yellowish brown, and at the sides there is a distinct yellow line. Younger specimens may have some black hairs interspersed in the fur of the upperparts. The hairs of the underparts are grey at the bases and white at the tips, but those in a region of variable size on the chest are completely white. The underparts become lighter in color with age. The ears are dark brown and mostly naked. The tail is grayish brown and there is scarcely any difference in color between the upper and lower side. The hindfeet are covered with thin pale hairs. Juvenile individuals are dark brown to blackish, with the underparts dark gray in color, except for the well-defined white patch at the chest. In 41 specimens, the total length ranges from 300 to 330 mm (11.8 to 13 in), the head and body length from 136 to 166 mm (5.4 to 6.5 in), the hindfoot length from 33.5 to 38 mm (1.3 to 1.5 in), and the skull length from 34 to 37 mm (1.3 to 1.5 in).
Literature cited
- Allen, J.A. 1912. Mammals from western Colombia. Bulletin of the American Museum of Natural History 31:71-95.
- Musser, G.G. and Carleton, M.D. 2005. Superfamily Muroidea. Pp. 894–1531 in Wilson, D.E. and Reeder, D.M. (eds.). Mammal Species of the World: a taxonomic and geographic reference. 3rd ed. Baltimore: The Johns Hopkins University Press, 2 vols., 2142 pp. ISBN 978-0-8018-8221-0
- Weksler, M., A. R. Percequillo, and R.S. Voss. 2006. Ten new genera of oryzomyine rodents (Cricetidae: Sigmodontinae). American Museum Novitates 3537:1–29.