Often called a "living fossil"* (a term I, as an evolutionary biologist, don't especially like, but it's used all the time) the coelacanth was thought to have gone extinct at the end of the Cretaceous period. However, it was rediscovered in a south African fish market in 1938 by museum curator Marjorie Courtenay Latimer (after whom the genus Latimeria is named). Another species, the Indonesian coelacanth was discovered in 1999, but has never, until now, been filmed alive in habitat.

Coelacanths are members of a group called the lobe-finned fishes. This group is characterized by fins supported by muscular, bony "limb buds", rather than fin rays, as in most of the rest of what we think of as "fishes". An interesting fact about lobe-finned fishes is that YOU are a lobe-finned fish (at least when defined cladistically).

*possibly more accurately described as a Lazarus taxon.