What is a Coelacanth?
Coelacanths belong to the subclass Actinistia, a group of lobed-finned fish related to lungfish and certain extinct Devonian fish such as osteolepiforms, porolepiforms, rhizodonts, and Panderichthys. Coelacanths were thought to have gone extinct in the Late Cretaceous (the nature of this epoch is in the picture), around 66 million years ago, but were rediscovered in 1938 off the coast of South Africa.
The coelacanth was long considered a “living fossil” because it was believed to be the sole remaining member of a taxon otherwise known only from fossils, with no close relations alive, and to have evolved into roughly its current form approximately 400 million years ago. Several recent studies have shown that coelacanth body shapes are much more diverse than was previously thought.