Sciurini is a

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English language, English is in the discipline of anthropology. This definition is contested, in p ...

that includes about forty species of

squirrel Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...

s,Thorington and Hoffmann, 2005, p. 754 mostly from the Americas. It includes five living genera—the American dwarf squirrels, ''

Microsciurus ''Microsciurus'' or dwarf squirrels is a genus of squirrels from the tropical regions of Central and South America. Taxonomy and systematics Recent DNA analysis has shown that there is some confusion regarding the traditional classification o ...

''; the Bornean '' Rheithrosciurus''; the widespread American and Eurasian tree squirrels of the genus ''

Sciurus The genus ''Sciurus'' contains most of the common, bushy-tailed squirrels in North America, Europe, temperate Asia, Central America and South America. Species The number of species in the genus is subject to change. In 2005, Thorington & Hoffma ...

'', which includes some of the best known squirrel species; the Central American ''

Syntheosciurus Bangs's mountain squirrel (''Syntheosciurus brochus'') is a poorly known species of tree squirrel, that only lives in Costa Rica and Panama. It can be found in mountain rain forests at an altitude between , and lives mainly in the tree tops, but ...

''; and the American pine squirrels, ''

Tamiasciurus Pine squirrels are squirrels of the genus ''Tamiasciurus'', in the Sciurini tribe, of the large family Sciuridae. Species This genus includes three species: *''Tamiasciurus hudsonicus'' — American red squirrel *''Tamiasciurus douglasii'' ...

''. Like other

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

squirrels, they are sometimes referred to as

tree squirrel Tree squirrels are the members of the squirrel Family (biology), family (Sciuridae) commonly just referred to as "squirrels." They include more than 100 arboreal species native to all continents except Antarctica and Oceania. They do not form a ...

Taxonomy

The name "Sciurini" was first employed by

Hermann Burmeister Karl Hermann Konrad Burmeister (also known as Carlos Germán Conrado Burmeister) (15 January 1807 – 2 May 1892) was a German Argentine zoologist, entomologist, herpetologist, botany, botanist, and coleopterologist. He served as a professor at ...

in 1854, who used it for the entire squirrel family. In his influential 1945 classification of mammals,

George Gaylord Simpson George Gaylord Simpson (June 16, 1902 – October 6, 1984) was an American paleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the Modern synthesis (20th century), modern ...

included four

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

of squirrels in Sciurini, which he recognized as one of eight

tribes The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to conflic ...

within the subfamily Sciurinae (including all squirrels except the

flying squirrel Flying squirrels (scientifically known as Pteromyini or Petauristini) 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 ar ...

s): ''

'', ''

'', and ''

Sciurillus The Neotropical pygmy squirrel (''Sciurillus pusillus'') is a South American species of tree squirrel, being the only living species in the genus ''Sciurillus'' and the subfamily Sciurillinae. Genetic analysis has shown it to be the sister group ...

''. He also classified '' Rheithrosciurus'' as "?Sciurini ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

''" (of uncertain placement).Simpson, 1945, p. 78 This grouping derives from

Reginald Innes Pocock Reginald Innes Pocock F.R.S. (4 March 1863 – 9 August 1947) was a British zoologist. Pocock was born in Clifton, Bristol, the fourth son of Rev. Nicholas Pocock and Edith Prichard. He began showing interest in natural history at St. Edward ...

, who united these squirrels in 1923 as the subfamily Sciurinae.Moore, 1959, p. 177 In 1959,

Joseph Curtis Moore {{Short pages monitor