Rattus is a genus of muroidrodents, 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 Rattusspecies are the black rat (R. rattus) and the brown rat (R. norvegicus). The group is generally known as the Old World rats or true rats and originated in Asia. Rats are bigger than most Old World mice, which are their relatives, but seldom weigh over 500 grams (1.1lb) in the wild.
Taxonomy of Rattus
The genus Rattus is a member of the giant subfamily Murinae.
The genus Rattus proper contains 64 extant species. A subgeneric breakdown of the species has been proposed, but does not include all species.
Himalayan field rat (Rattus nitidus) – originally native to Bhutan, China, India, Myanmar, Nepal, Thailand, and Vietnam (presence uncertain in Bangladesh), but now introduced to Indonesia, the Philippines, and Palau
Brown rat (Rattus norvegicus) – originally native to southeastern Siberia, northeastern China, and parts of Japan, but now introduced worldwide except Antarctica
Molecular evidence suggests that Rattus originated in the Late Miocene and that it experienced an exceptionally rapid burst of diversification during the Pleistoceneepoch.
Fossil species
In contrast to the large number of living species, as of 2024, just four fossil species have been placed in Rattus proper:
↑Thomson, Vicki; Wiewel, Andrew; Chinen, Aldo; Maryanto, Ibnu; Sinaga, M. H.; How, Ric; Aplin, Ken; Suzuki, Hitoshi (2018). "A perspective for resolving the systematics of Rattus, the vertebrates with the most influence on human welfare". Zootaxa. 4459 (3): 431–452. doi:10.11646/zootaxa.4459.3.2. PMID30314119. S2CID52975664.
↑Chang, M.; Zhang, C.; etal. (January 2023). "A new Rattus species and its associated micromammals from the Pliocene Yangyi Formation in Baoshan, Western Yunnan, China". Journal of Vertebrate Paleontology. 43 (1) e2249063. doi:10.1080/02724634.2023.2249063.