- 1940 – The Cascade mountain wolf was hunted to extinction.
- 1942 – The Texas wolf was purposefully driven to extinction.
- 1942 – The last confirmed sighting of the Barbary lion, although unconfirmed reports surfaced until 1970.
- 1952 – Last reliable report of the Caribbean monk seal.
- 1952 – The Bernard’s wolf was hunted to extinction.
- 1956 – The crescent nail-tail wallaby and imperial woodpecker were last recorded.
- 1957 – The Scioto madtom, a species of fish, is last collected.
- 1960 – The Mexican grizzly bear was exterminated around this time.
- 1962 – The red-bellied gracile opossum was last recorded in Argentina.
- 1964 – The Hawaii chaff flower of the Hawaiian islands becomes extinct because of habitat loss.
- 1965 – Last sighting of the turgid-blossom pearly mussel, an American mussel.
- 1966 – The last Arabian ostrich died around this time.
- 1970 – The Caspian tiger becomes extinct primarily due to habitat loss, hunting, and loss of prey.
- 1972 – The endemic to Jamaica Mason River myrtle becomes extinct.
- 1974 – The last known Japanese sea lion is captured off the coast of Rebun Island, Hokkaido.
- 1976 – Last sightings of the Javan tiger.
- 1981 – The Puhielelu hibiscadelphus becomes extinct.
- 1981 – Last sighting of the green-blossom pearly mussel, an American mussel.
- 1981 – The Southern gastric-brooding frog (Rheobatrachus silus) became extinct probably due to habitat destruction and disease.
- 1983 – Last unconfirmed spotting of the kouprey (Bos sauveli), last absolute confirmed spotting was in 1969/70. Declared as “most likely to be extinct” by the IUCN.
- 1983-84 – The 24-rayed sunstar (Heliaster solaris), the Galapagos black-spotted damselfish and the Galapagos stringweed likely become extinct due to climate change.
- 1985 – The Northern gastric-brooding frog (Rheobatrachus vitellinus) became extinct probably due to habitat destruction and disease.
- 1987 – The last Kauaʻi ʻōʻō (Moho braccatus), a male, is recorded singing a mating call. The species was never heard from again and was declared extinct.
- 1989 – The golden toad of Costa Rica becomes extinct, perhaps because of climate change.
- 1990 – The dusky seaside sparrow was officially declared extinct in December 1990. The last definite known individual died on 17 June 1987.
- 1994 – Saint Croix racer, a snake native to the Virgin Islands, declared extinct.
- 1994 – Levuana moth from Hawaii goes extinct.
- 1997 – The Hainan ormosia (a species of legume) which was native to China is no longer seen.