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.Poaching vulnerability
Overall numbers of black and white rhinos have been rising, but some subspecies have been particularly vulnerable to poaching by criminal gangs who want to trade the animals' valuable horns.
Simon Stuart, chair of the IUCN Species Survival Commission, told BBCNews: "They had the misfortune of occurring in places where we simply weren't able to get the necessary security in place.
"You've got to imagine an animal walking around with a gold horn; that's what you're looking at, that's the value and that's why you need incredibly high security."
Another focus for this year's list is Madagascar and its reptiles. The report found that 40% of terrestrial reptiles are threatened. But it also says that new areas have been designated for conservation.