Leptomys paulus is a small rodent belonging to the family Muridae endemic to New Guinea.
L. paulus has a head and body length of between 117 and 132 mm, and a tail length of between 138 and 163 mm. Its ears are 18 to 23 mm, dark brown in colour and have a few dark hairs, its feet are 31 to 36 mm . It can weigh up to 52 g.Its thick and soft fur is dark reddish brown on dorsal parts, yellowish on its sides and grayish white on the ventral parts. There is a hairless strip of skin that extends from the middle of the shoulders towards the forehead. It has long whiskers (60 mm) and white cheeks with a darker colour around the eyes. The tail is almost hairless with a white tip.[1]
The species has been observed in the tropical low-montane regions of eastern New Guinea, between 1,240 and 1,540 m.[1]