Ethiopian amphibious rat

The Ethiopian amphibious rat, or Ethiopian water mouse (Nilopegamys plumbeus), is an insectivorous, semiaquatic rodent and the only species in the genus Nilopegamys, in the family Muridae. Only one specimen is known. Wilfred Osgood collected it in 1928 in a trap set along the Lesser Abay River, near its source at about 2,600 metres in the highlands of northwestern Ethiopia. It is regarded as the most aquatically adapted African murid, with webbed feet and the largest cranial capacity of any African muroid sampled. The species is rated critically endangered and may already be extinct, because overgrazing by livestock has largely destroyed its highland wetland habitat, and two attempts to find it again have failed.