The coelacanth is the fish widely called a living fossil after a living specimen was discovered in 1938.
Scientists had known coelacanths only from fossils and believed the group had disappeared about 66 million years ago. That changed when museum curator Marjorie Courtenay-Latimer recognized an unusual fish caught near South Africa. The species was named Latimeria chalumnae in recognition of the discovery and the Chalumna River region.
Coelacanths have distinctive fleshy, limb-like paired fins and a three-lobed tail. Their lineage has ancient roots, but the phrase living fossil can mislead: modern coelacanths have also evolved since their ancient relatives and are not unchanged relics.
A second living species, Latimeria menadoensis, was identified in Indonesia in 1997. Coelacanths inhabit deep rocky environments and are difficult to study because they are rarely encountered and generally live at substantial depth.