Taxonomic revision and phylogenetic position of the flying squirrel genus Biswamoyopterus (Mammalia, Rodentia, Sciuridae, Pteromyini) on the northern Indo-China peninsula

Abstract

The flying squirrel genus Biswamoyopterus (Rodentia: Sciuridae: Pteromyini) was once considered to contain two species, Biswamoyopterus biswasi from northeastern India and B. laoensis from central Laos, identified from morphological characteristics of single specimen. However, based on similar morphological characteristics of two samples of the genus Biswamoyopterus collected recently from northern Laos and northern Myanmar, these can now be regarded as one species, B. biswasi being the correct name with B. laoensis the synonym. Small genetic distances among mitochondrial DNA and nuclear DNA strongly support these two samples as representatives of the same species. Thus, Biswamoyopterus is a monotypic genus, and the phylogenetic analyses strongly supported Biswamoyopterus as an independent genus of Pteromyini, acting as a sister group to Aeromys. Biswamoyopterus biswasi is distributed in the northern Indo-China peninsula, where it is exposed to a series of threats, such as intense hunting activity, illegal trade, and rapid habitat loss; this should warrant its classification as critically endangered according to the International Union for Conservation of Nature (IUCN) Red List criteria. Here, new specimen records for B. biswasi from northern Laos and northern Myanmar are presented.