Cuscomys
Cuscomys is a genus of rodents found in the Andes of Cusco in southern Peru. These relatively large chinchilla rats are dark grey with a distinct white line running from the crown to the nose. The genus was coined in 1999 when "C. ashaninka" was scientifically described, but later it was discovered that "C. oblativus", a species traditionally placed in the genus "Abrocoma", actually belonged in "Cuscomys". They are very poorly known, as "C. ashaninka" only is known from the holotype, while "C. oblativus" usually has been considered extinct, as it was only known from remains found in 1912 , buried alongside people in ancient Inca tombs at the Machu Picchu ruins. However, photos of a rodent taken at the ruins in late 2009 likely show this species. It is unclear if the "Cuscomys" truly are extremely rare, as they may be easily overlooked due to their remote distributions and arboreal habits.