A rhinoceros subspecies is almost extinct.

On Monday, the world's last male northern white rhino, Sudan, died at 45 years of age.

Sudan — who is named for his country of birth and lived under the protection of armed guards at the Ol Pejeta Conservancy in Kenya, away from poachers — suffered from a degenerative muscle and bone condition and was euthanized.

Fortunately, scientists were able to gather genetic material that could one day be used to create more northern white rhinos through IVF. Sudan also left behind a daughter and granddaughter, so there's a flicker of hope for the wildlife preservation community.

Even so, there are numerous other animal species and subspecies that are in danger of perishing for good. The Amur leopard and Sumatran elephant are just two of 19 species categorized as "critically endangered" by the World Wildlife Fund, while the white-rumped vulture and Chinese pangolin have been given the equivalent classification on the IUCN Red List.

Keep scrolling to see 12 animals that are on the verge of extinction