coelacanth
definition
an ancient fish known from fossils and considered a living fossil due to its presence in the fossil record dating back over 400 million years
example
The coelacanth was once thought to be extinct until it was rediscovered off the coast of South Africa in 1938.
synonyms
none
word origin — from Greek 'koilos' meaning 'hollow' and 'akantha' meaning 'spine'