Wikipedia
Coelacanthopsis is an extinct genus of lobe-finned fish which lived during the Carboniferous period.
The Coelacanth is the only living example of the fossil Coelacanth fishes Actinistia. They are also the closest link between fish and the first amphibian creatures which made the transition from sea to land in the Devonian period (408-362 Million Years Ago). That such a creature could have existed for so long is nearly incredible, but some say that the cold depths of the West Indian ocean at which the Coelacanth thrives, and the small number of predators it has, may have helped the species survive eons of change. The Coelacanth was first discovered in 1938 by Marjorie Courtenay Latimer, the curator of a small museum in the port town of East London, as she was visiting a fisherman who would let her search through his boat's catch for interesting specimens. Ironically, Marjorie was only visiting the sea captain to wish him a happy Christmas when she first spotted the Coelacanth's oddly shaped, blue-gray fin protruding from beneath a mountain of fish. Marjorie brought back the specimen to the museum where she compared it against images of known species, and ultimately realized what she had was no ordinary fish. After sending a rough drawing of the fish to Professor J.L.B. Smith, at Rhodes University, Grahamstown, who in turn confirmed that the creature she had discovered on the boat's deck was indeed a prehistoric fish, a Coelacanth to be exact.
Since then, Coelacanth populations have been found near Indonesia, South Africa, and other unexpected places. While there have been enough sightings of the creature to indicate that there is more than one area where the species exists, it remains a highly protected and mysterious animal, a living fossil which may, or may not be the only creature from our past which has survived millions of years of evolution.
Some place it in the family Rhabdodermatidae.