Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels, and flying squirrels. Squirrels are indigenous to the Americas, Eurasia, and Africa, and were introduced by humans to Australia. The earliest known fossilized squirrels date from the Eocene epoch, and among other living rodent families, the squirrels are most closely related to the mountain beaver and to the dormice.
Flying squirrels are a tribe of 50 species of squirrels in the family Sciuridae. Despite their name, they are not in fact capable of full flight in the same way as birds or bats, but they are able to glide from one tree to another with the aid of a patagium, a furred skin membrane that stretches from wrist to ankle. Their long tails also provide stability as they glide. Anatomically they are very similar to other squirrels with a number of adaptations to suit their lifestyle; their limb bones are longer and their hand bones, foot bones, and distal vertebrae are shorter. Flying squirrels are able to steer and exert control over their glide path with their limbs and tail.
The Anomaluridae are a family of rodents found in central Africa. They are known as anomalures or scaly-tailed squirrels. The six extant species are classified into two genera.
The genus Petaurus contains flying phalangers or wrist-winged gliders, a group of arboreal possums native to Australia, New Guinea, and surrounding islands. There are eight species: the sugar glider, savanna glider, Krefft's glider, squirrel glider, mahogany glider, northern glider, yellow-bellied glider and Biak glider.
Mammalia is a class of animal within the phylum Chordata. Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is universally accepted; McKenna & Bell (1997) and Wilson & Reader (2005) provide useful recent compendiums. Many earlier ideas from Linnaeus et al. have been completely abandoned by modern taxonomists, among these are the idea that bats are related to birds or that humans represent a group outside of other living things. Competing ideas about the relationships of mammal orders do persist and are currently in development. Most significantly in recent years, cladistic thinking has led to an effort to ensure that all taxonomic designations represent monophyletic groups. The field has also seen a recent surge in interest and modification due to the results of molecular phylogenetics.
The long-eared flying mouse or long-eared scaly-tailed flying squirrel, is a species of flying mouse from western and central Africa. It is not actually a squirrel, nor a mouse, though it is a rodent. Not much is known about them because they are very hard to keep alive in captivity.
Sciuromorpha ( 'squirrel-like') is a rodent clade that includes several different rodent families. It includes all members of the Sciuridae as well as the mountain beaver species.
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.
Anomalurus is the largest genus in the rodent family Anomaluridae, with four species. It is the only genus in the subfamily Anomalurinae.
Beecroft's flying squirrel or Beecroft's scaly-tailed squirrel, is a species of rodent in the family Anomaluridae. Some authorities consider it to be monotypic within the genus Anomalurops. Its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, and plantations. It is threatened by habitat destruction but is a common species with a wide range and the International Union for Conservation of Nature has rated its conservation status as being of "least concern".
Pel's flying squirrel or Pel's scaly-tailed squirrel is a species of rodent in the family Anomaluridae. It is found in Liberia, Ivory Coast, and Ghana, where it lives in lowland tropical rainforests. It is named after Hendrik Pel.
The dwarf scaly-tailed squirrel is a species of rodent in the family Anomaluridae. It is found in Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Equatorial Guinea, Gabon and Uganda. The species is nocturnal and arboreal and lives in subtropical or tropical lowland rainforest. Membranes attached to its limbs and tail enable it to glide between trees. This squirrel is currently not considered to be threatened by habitat destruction; "much of the habitat within parts of the known range of this species is relatively intact, and the species is unlikely to be experiencing any significant declines."
The pygmy scaly-tailed flying squirrel is a species of rodent in the family Anomaluridae. It is found in Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Equatorial Guinea, and Uganda. Its natural habitat is subtropical or tropical moist lowland forests.
The red and white giant flying squirrel is a species of rodent in the family Sciuridae. It is a very large, dark rufous-red, buff and white flying squirrel found in forests at altitudes of 800–3,500 m (2,600–11,500 ft) in mainland China and 1,200–3,750 m (3,940–12,300 ft) in Taiwan, although the population of the latter island is distinctive and likely better regarded as a separate species, the Taiwan giant flying squirrel. Additionally, the red and white giant flying squirrel possibly ranges into northeastern South Asia and far northern Mainland Southeast Asia. This squirrel has a wide range and is relatively common, and the International Union for Conservation of Nature lists it as being of "least concern".
The Cameroon scaly-tail, also referred to as the Cameroon anomalure, flightless anomalure or flightless scaly-tail, is a rodent species endemic to West Central Africa. The scientific literature has never reported observations of live individuals. The taxonomic classification of the species has been subject to recent revision.
Lord Derby's scaly-tailed squirrel is an anomalurid rodent native to Africa. It was named after Edward Smith-Stanley, 13th Earl of Derby.
Zenkerella is a genus of rodent, the only member of the family Zenkerellidae. It was formerly classified in Anomaluridae until phylogenetic studies made its distinctiveness clear. While the Anomalurus of the family Anomaluridae has gliding membranes between its forelimb and hindlimb, the Zenkerella has no such adaptation. It is estimated from fossil records that this divergence might have occurred in the middle of the Eocene.
