Tarsiiformes are a group of primates that once ranged across Europe, northern Africa, Asia, and North America, but whose extant species are all found in the islands of Southeast Asia. Tarsiers are the only living members of the infraorder; other members of Tarsiidae include the extinct Tarsius eocaenus from the Eocene, and Tarsius thailandicus from the Miocene. Two extinct genera, Xanthorhysis and Afrotarsius, are considered to be close relatives of the living tarsiers, and are generally classified within Tarsiiformes, with the former grouped within family Tarsiidae, and the latter listed as incertae sedis (undefined). Omomyids are generally considered to be extinct relatives, or even ancestors, of the living tarsiers, and are often classified within Tarsiiformes.
The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae. Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea. Some refer to the subfamily as the Microtinae or rank the taxon as a full family, the Arvicolidae.
The suborder Myomorpha contains 1,524 species of mouse-like rodents, nearly a quarter of all mammal species. Included are mice, rats, gerbils, hamsters, lemmings, and voles. They are grouped according to the structure of their jaws and molar teeth. They are characterized by their myomorphous zygomasseteric system, which means that both their medial and lateral masseter muscles are displaced forward, making them adept at gnawing. As in the hystricognathous rodents, the medial masseter muscle goes through the eye socket, a feature unique among mammals. Myomorphs are found worldwide in almost all land habitats. They are usually nocturnal seed-eaters.
Castorimorpha is the suborder of rodents containing the beavers and the kangaroo rats. A 2017 study using retroposon markers indicated that they are most closely related to the Anomaluromorpha and Myomorpha.
The water voles are large voles in the genus Arvicola. They are found in both aquatic and dry habitat through Europe and much of northern Asia. A water vole found in Western North America was historically considered a member of this genus, but has been shown to be more closely related to members of the genus Microtus. Head and body lengths are 12–22 cm, tail lengths are 6.5–12.5 cm, and their weights are 70–250 g. The animals may exhibit indeterminate growth. They are thick-furred and have hairy fringes on their feet that improve their swimming ability.
The genus Lemmus contains several species of lemming sometimes referred to as the true lemmings. They are distributed throughout the Holarctic, particularly in the Palearctic.
Mice in the genus Dendromus are commonly referred to as African climbing mice or tree mice, although these terms are often used to describe all members of the subfamily Dendromurinae. The genus is currently restricted to sub-Saharan Africa, but fossils classified in the genus have been found from Late Miocene deposits in Arabia and Europe.
Anomaluromorpha is a clade that unites the anomalures, springhares, and zenkerella. It has alternately been designated as either a suborder or infraorder. Most recently, Carleton & Musser 2005 recognized it as one of five suborders of rodents.
The grey red-backed vole or the grey-sided vole is a species of vole. An adult grey red-backed vole weighs 20-50 grams. This species ranges across northern Eurasia, including northern China, the northern Korean Peninsula, and the islands of Sakhalin and Hokkaidō. It is larger and longer-legged than the northern red-backed vole, which covers a similar range and it is also sympatric with the Norwegian lemming.
The reed vole is a species of vole. It is found in northern and central Eurasia, including northern China and the Korean Peninsula. This species is somewhat larger and longer-tailed than most other voles.
Meriones is a rodent genus that includes the gerbil most commonly kept as a pet, Meriones unguiculatus. The genus contains most animals referred to as jirds, but members of the genera Sekeetamys, Brachiones, and sometimes Pachyuromys are also known as jirds. The distribution of Meriones ranges from northern Africa to Mongolia. Meriones jirds tend to inhabit arid regions including clay desert, sandy desert, and steppe, but are also in slightly wetter regions, and are an agricultural pest.
Sciurini is a tribe that includes about forty species of squirrels, mostly from the Americas. It includes five living genera—the American dwarf squirrels, Microsciurus; the Bornean Rheithrosciurus; the widespread American and Eurasian tree squirrels of the genus Sciurus, which includes some of the best known squirrel species; the Central American Syntheosciurus; and the American pine squirrels, Tamiasciurus. Like other arboreal squirrels, they are sometimes referred to as tree squirrels.
The Balkan snow vole, also known as Martino's snow vole, is the only member of the genus Dinaromys. Eight subspecies of this vole have been recognized from southern parts of Europe. The genus name means "Dinaric mouse", referring to the Dinaric Alps. The Balkan snow vole is a living fossil, the only living species in the tribe Pliomyini, and might arguably better be placed in Pliomys, a genus established for its fossil relatives even before the Balkan snow vole was scientifically described.
The lemming vole is a species of rodent in the family Cricetidae. It is found only in the Russian Federation.
The Zaisan mole vole, or eastern mole vole, is a species of rodent in the family Cricetidae. It is found in central Asia.
Maximowicz's vole is a species of rodent in the family Cricetidae. It is found in northeastern China, Mongolia, and eastern Russia.
The creeping vole, sometimes known as the Oregon meadow mouse, is a small rodent in the family Cricetidae. Ranging across the Pacific Northwest of North America, it is found in forests, grasslands, woodlands, and chaparral environments. The small-tailed, furry, brownish-gray mammal was first described in the scientific literature in 1839, from a specimen collected near the mouth of the Columbia River. The smallest vole in its range, it weighs around 19 g (0.67 oz). At birth, they weigh 1.6 g (0.056 oz), are naked, pink, unable to open their eyes, and the ear flaps completely cover the ear openings. Although not always common throughout their range, there are no major concerns for their survival as a species.
The Clethrionomyini are a tribe of forest voles in the subfamily Arvicolinae. This tribe was formerly known as Myodini, but when genus Myodes was deemed to be a junior synonym, the tribe was renamed. Species in this tribe are:
A lemming is a small rodent, usually found in or near the Arctic in tundra biomes. Lemmings form the subfamily Arvicolinae together with voles and muskrats, which form part of the superfamily Muroidea, which also includes rats, mice, hamsters, and gerbils. In popular culture, a longstanding myth holds that they exhibit herd mentality and jump off cliffs, committing mass suicide.
?Oryzomys pliocaenicus is a fossil rodent from the Hemphillian of Kansas, central United States. It is known from a single mandible with the back part missing. All three molars are present, but very worn. Together, the molars are 3.6 mm long. The fossil was discovered in 1935 and described in 1939 as a possible species of Oryzomys. Later authors doubted this allocation and suggested that it may instead belong in Bensonomys or Jacobsomys, but the material may not allow a definite identification.
