Coelacanth

Coelacanth is a giant fish species that has been alive since its evolution some 400 million years ago. It was believed to be extinct until live specimens were discovered off the coast of South Africa in 1938. Recently, palaeontologists discovered the fossil of a 66 million year old specimen in a block of phosphate. Though the fish rarely grows beyond 2m in the current times, it used to grow as large as a great white shark in the ancient times.