Comments: | Ellerman (1940) reviewed the history of sciurid classification. The first modern classification (Pocock, 1923) recognized six subfamilies: Sciurinae, Tamiasciurinae, Funambulinae, Callosciurinae, Xerinae, and Marmotinae. We do not accept the use of Nannosciurinae (Forsyth Major, 1895) as a senior synonym for Callosciurinae (Pocock, 1923), as proposed by McKenna and Bell (1997). Simpson (1945) recognized the same taxa, but all at the tribal level. Ellerman (1940) avoided formal designation, but recognized seven "sections" in the Sciurus "group," which often do not conform with the above. Moore (1959) recognized Simpson's six tribes and, in addition, Ratufini and Protoxerini for certain genera that had previously been included in Funambulini. Black (1963) elevated Tamiini to tribal level (previously in Marmotini). Gromov et al. (1965) elevated the ground squirrels to subfamily rank, Marmotinae, which included the tribes Tamiini Black, Otospermophilini Gromov, Citellini Gromov, Marmotini Simpson (part), and Cynomyini Gromov. He also recognized the subfamilies Xerinae and Sciurinae, but did not treat any other groups. Heaney (1985) recommended that the subtribe Hyosciurina of Moore (1959) be discarded because it lacks defining characters, and that the component genera (Hyosciurus, Prosciurillus, Rubisciurus, and Exilisciurus) be retained in tribe Callosciurini Simpson, 1945. Emry and Thorington (1984) submerged Tamiasciurini in Sciurini and Tamiini in Marmotini. They also (1982) described the oldest known sciurid, Douglassciurus (formerly Protosciurus), which they interpreted as an arboreal form similar to Sciurus from which both flying squirrels and ground squirrels have been derived. These authors treated flying squirrels as a monophyletic sister group to other squirrels, either as a family (Pocock, 1923) or subfamily (other authors). The monophyly of flying squirrels has been both supported (Thorington, 1984) and questioned (Hight et al., 1974). A catalogue of Indian sciurids was presented by Agrawal and Chakraborty (1979). Molecular studies (Mercer and Roth, 2003; Steppan et al., 2004) force a revision of the higher level systematic arrangement of the Sciuridae, which is adopted here. |