No wild black rhinos remain in West Africa, according to the latest global assessment of threatened species.
The Red List, drawn up by the International Union for Conservation of Nature (IUCN), has declared the subspecies extinct.
A subspecies of white rhino in central Africa is also listed as possibly extinct, the organisation says.
The annual update of the Red List now records more threatened species than ever before.
The IUCN reports that despite conservation efforts, 25% of the world's mammals are at risk of extinction. As part of its latest work it has reassessed several rhinoceros groups.
