Have you ever heard of these animals?

Well, they have long since been extinguished.

1. JAPANESE SEA LION 

The hunting and the destruction of its habitat by the 2nd World War ended with this species. A calf was captured in 1974. In 2007, the government of South Korea announced a plan to introduce the California sea lion into the spaces where its relative used to live.

2. MEXICAN GRIZZLY BEAR 

These huge grizzly bears came to walk through Mexican lands. This species was hunted until its disappearance because it ate the cattle of the ranches. Only 30 of them remained until 1960, but in 1964 it was considered totally extinct.

3. CYANERPES 

The introduction of non-native species of Hawaii such as pigs, cats and rats, contributed to the extinction of this bird. It is still listed as "in danger of extrusion" but none has been found despite the exhaustive searches. It was declared extinct in 2004.