The grey-faced sengi (Rhynchocyon udzungwensis) is a species of elephant shrew that is endemic to the Udzungwa Mountains of south-central Tanzania. The discovery of the species was announced in January 2008; only 15 species of elephant shrew were known until then, and the last discovery was made more than 120 years ago. As the name implies, the species is characterised by a distinctive grey face and a black rump, as well as being larger than the other species of elephant shrews.