Discovery of a new species of giant flying squirrel (Petaurista) from northwest Yunnan, China, sheds light on the origin and diversification of the genus

Abstract

Petaurista is the largest and most taxonomically complex genus of extant flying squirrels and occurs in forests of Asia. Eight Petaurista specimens collected from both sides of the Nu (Salween) River in northwest Yunnan Province, China, did not match the diagnosis of any currently known species. We undertook a comprehensive morphological and genetic comparison between these specimens and other Petaurista species. Our results suggest that: (i) the northwest Yunnan specimens represent a new species that has been named Petaurista nujiangensis sp. nov.; (ii) magnificus, sybilla, and yunanensis and mishmiensis should be recognized as subspecies of Petaurista albiventer, Petaurista marica, and Petaurista nobilis, respectively; (iii) mechukaensis and muzongensis should be synonymized with Petaurista nobilis mishmiensis; (iv) there are 14 species within the genus Petaurista; and (v) Petauria is a distinct fossil genus, not related to Petaurista, and includes helleri and tetyukhensis. The estimated time of divergence and inferred ancestral distribution suggest that Petaurista originated in the Hengduan Mountains in the Miocene and underwent early diversification in situ. It subsequently spread to the Himalayas, Southeast Asia, and East Asia during the Late Miocene and Early Pliocene. Climate change and fluctuating sea levels during the Pliocene and Pleistocene then led to subspecies differentiation.