Coelacanths are large fish, with living examples reaching over six feet in length. Extinct coelacanths, such as Mawsonia, could grow even larger, reaching lengths of over 17 feet.
Coelacanths have armor-like scales and large eyes. They are members of a group called “lobe-finned” fishes, whose fins are at the end of fleshy, lobe-like limbs. This is in contrast to ray-finned fishes, whose fins are composed of spiny bones that protrude from the fish’s body, rather than at the end of limbs.
One of the most distinctive features of most coelacanths is the small tuft of fin rays in the middle of the tail, which looks a bit like a smaller tail sprouting from their actual tail.