A fish returned from the fossil record
The coelacanth was known as a Cretaceous fossil until a living one was caught off South Africa in 1938. A second species was later found in Indonesia.
On 22 December 1938 Marjorie Courtenay-Latimer found an unusual fish in a catch at East London. J. L. B. Smith recognised it as a coelacanth, a group last seen in rocks about 66 million years old, and published the identification in Nature. He named it Latimeria chalumnae. A second species, L. menadoensis, turned up in a Sulawesi fish market in the 1990s.
Living coelacanths are not paused fossils. They are modern animals, deep-water, nocturnal, with a lineage that continued to evolve after the fossils we happened to know. 'Unchanged for millions of years' is the part of the story that does not survive contact with the anatomy. The survival of the lineage is the part that does.
Caveats
- The 1938 fish was one specimen. Populations, small and local, have since been found and are threatened.
- Coelacanths are lobe-finned fishes related to the lineage that produced tetrapods. They are not our ancestor. They are a cousin that stayed in the water.
Sources
- 1Smith J. L. B.. A living fish of Mesozoic type. Nature 143, 1939.