There may be many more “extinct” animals waiting to be rediscovered than conservation biologists previously thought. Categorizing an animal species as extinct has rested upon two criteria: It has not been seen for more than 50 years, or an exhaustive research has come up empty. But “extinct” animals occasionally turn up again, and some species have disappeared more than once.
1. Tasmanian Tiger
This tiger has been extinct for a long time, and it has been so because of its habitat loss and hunting. They have been chasing and killing the livestock, so they were driven out and hunted. They eventually got officially extinct in Tasmania in 1936. Unfortunately, conservation efforts had come too late. The largest marsupial carnivore in the world, the thylacine was commonly known as the “Tasmanian tiger”, because of its stripes on its back. In spite of its fierce reputation, the tiger was semi-nocturnal and was described as really shy, usually avoiding contact with people. The fossilized remains of these animals have been found in Papua New Guinea, Tasmania and throughout the Australian mainland. But apparently the tiger was seen by many people, and most of these encounters were reported in Australia where these tigers have been extinct since the 1800s.