The precise limits of distribution of this species are unclear. It is reliably recorded from Cambodia, Viet Nam, and from southern Lao PDR, where Duckworth et al. (1999) reported them as far north as about 15.4Â°N. To the west of this, they extend to Kanchamburi Province in southern Thailand right to the Bay of Bengal in Myanmar, as Groves (2001) notes intersecting between the distributions of T. obscurus and T. phayrei. Records from Assam and elsewhere in north-east India, which have been attributed to this species, presumably relate to another species and indeed it is not mentioned as part of the range of this species by Groves (2005).