''Rattus'' is a

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 ...

of muroid

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 ...

s, all typically called rats. However, the term rat can also be applied to rodent species outside of this genus.

Species and description

The best-known ''Rattus''

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

are the black rat (''R. rattus'') and the

brown rat The brown rat (''Rattus norvegicus''), also known as the common rat, street rat, sewer rat, wharf rat, Hanover rat, Norway rat and Norwegian rat, is a widespread species of common rat. One of the largest Muroidea, muroids, it is a brown or grey ...

(''R. norvegicus''). The group is generally known as the Old World rats or true rats and originated in

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. Rats are bigger than most Old World mice, which are their relatives, but seldom weigh over in the wild.

Taxonomy of ''Rattus''

The genus ''Rattus'' is a member of the giant subfamily Murinae. Several other murine genera are sometimes considered part of ''Rattus'': ''

Lenothrix The gray tree rat (''Lenothrix canus'') is a species of rodent in the family Muridae. monotypic taxon, only species in the genus ''Lenothrix''. It is found in forests in Indonesia and Malaysia. A common species, the International Union for Conse ...

'', '' Anonymomys'', '' Sundamys'', '' Kadarsanomys'', '' Diplothrix'', '' Margaretamys'', '' Lenomys'', '' Komodomys'', '' Palawanomys'', '' Bunomys'', ''

Nesoromys The Ceram rat (''Nesoromys ceramicus''), also known as the Seram Island mountain rat, is a species of rodent in the family Muridae. It is found only in Seram Island, Indonesia, where it has been recorded on Mount Mansuela. It is the only speci ...

'', ''Stenomys'', '' Taeromys'', '' Paruromys'', '' Abditomys'', '' Tryphomys'', '' Limnomys'', '' Tarsomys'', '' Bullimus'', '' Apomys'', '' Millardia'', '' Srilankamys'', '' Niviventer'', '' Maxomys'', '' Leopoldamys'', '' Berylmys'', '' Mastomys'', '' Myomys'', '' Praomys'', '' Hylomyscus'', '' Heimyscus'', '' Stochomys'', '' Dephomys'' and '' Aethomys''. The genus ''Rattus'' proper contains 64 extant species. A subgeneric breakdown of the species has been proposed, but does not include all species.

Species

Phylogeny

The following phylogeny of selected ''Rattus'' species is from .

Fossil species

In contrast to the large number of living species, as of 2024, just four fossil species have been placed in ''Rattus'' proper: * ''Rattus baoshanensis'' - Late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Thailand * ''Rattus pristinus'' - Early Pleistocene China * ''Rattus miyakoensis'' - Late Pleistocene Japan

References

{{Authority control . Rodent genera Taxa named by Gotthelf Fischer von Waldheim Extant Pleistocene first appearances