[citation needed] For more than a century since its description by Oldfield Thomas, the only species in the genus was thought to be the western woolly flying squirrel (E. cinereus), which is found in northern Pakistan and northwestern India.

[2][4][5] There are currently three known species in the genus:[1][2] The cheek teeth are unique as they are both flat-crowned and high crowned (hypsodont), setting Eupetaurus apart from other squirrels and suggesting that they feed on very abrasive plant material, including pine needles.

[2][6][7] The western woolly flying squirrel has a grizzled-grey pelage with pronounced frosting, in contrast to the more saturated brown coloration of the two other species, and has more robust cusps and cheek teeth.

Some of their arguments were based on poorly drawn and labeled diagrams of the cranium and lower jaw of E. cinereus.

Zahler and Woods (1997) suggest instead that Eupetaurus is closely related to another genus of large flying squirrels, Petaurista.