The Asháninka arboreal chinchilla rat (Cuscomys ashaninka) is a large species of chinchilla rats from the Andes of far northern Cusco in Peru. It was first scientifically described in 1999. The animal has grey fur, with a white nose and lips, and a line of white fur running down its head. It is 30 cm (12 in) in length, with a tail of 20 cm (7.9 in). The first specimen of this species was discovered by Dr. Louise Emmons, a researcher of the Smithsonian Institution from Washington, D.C.. She found it by chance while climbing in the Vilcabamba Mountains near Machu Picchu.