The golden Oldfield mouse or golden thomasomys (''Thomasomys aureus'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

in the family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At over 870 species, it is either the largest or second-largest family ...

. It is found in

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

. Both the common and genus name commemorate the British zoologist

Oldfield Thomas Michael Rogers Oldfield Thomas (21 February 1858 – 16 June 1929) was a British zoologist. Career Thomas worked at the Natural History Museum, London, Natural History Museum on mammals, describing about 2,000 new species and subspecies for ...

who worked at the

Natural History Museum, London The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum (Lo ...

and studied South American rodents.

Description

The Golden Oldfield mouse is a large member of its

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Thomasomys ''Thomasomys'' is a genus of rodents in the family Cricetidae, named after British zoologist Oldfield Thomas. Nuclear DNA sequence analysis has indicated that it is a sister taxon to '' Rhagomys''. It contains the following species: * Anderson's ...

'' with a head-and-body length of . The dorsal fur is thick, coarse, and long, a golden-brown colour grizzled with grey, with a narrow dark line along the spine. The ventral fur consists of grey hairs with yellowish tips. The hind feet are up to long, the upper surfaces having dark patches extending to the bases of the digits, with orange or white margins. The tail is unicoloured and ringed, clad with short hair and lacking a "pencil" (tuft of hairs) at its tip. The tail is 125 to 140% of the head-and-body length.

Distribution and habitat

The species occurs in forests in the foothills of the Andes. Its range extends from western Venezuela and eastern Colombia through most of Ecuador and Peru, and western central Bolivia. It typically inhabits densely vegetated areas at altitudes of between .

Ecology

This mouse is partly arboreal. It has been found on horizontal branches making paths between the

moss Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...

es and

liverworts Liverworts are a group of non-vascular plant, non-vascular embryophyte, land plants forming the division Marchantiophyta (). They may also be referred to as hepatics. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in wh ...

, and also on the ground with well-worn routes among the grasses and clumps of moss. Nests have been found in trees a few metres above the ground. The diet includes vegetable matter, fruits, seeds and small

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

Status

The golden Oldfield mouse has a wide range and is a fairly common species in most parts of its range, though less common in Ecuador. Deforestation is occurring throughout its range and populations may be declining, but the total population is likely to be large and any downward trend in populations is probably slow, so the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

has assessed its conservation status as being of "

least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

References

{{Taxonbar, from=Q1760955 Thomasomys Mammals of Colombia Mammals described in 1860 Taxonomy articles created by Polbot