Coelacanths are an ancient group of fish, thought to be extinct until 1938 when a modern relative was found off the coast of South Africa. Andrew Wendruff, lead researcher at the University of Alberta, says previous Coelacanth fossils are dramatically different than these finds. Coelacanth evolution was previously thought to be inactive, and assumed their lifestyle and body shape had not changed.
According to the team at ScienceDaily.com, the new coelacanth fossil was found in the Rocky Mountains near Tumbler Ridge, British Columbia. This area in the eastern range of the Rockies is much different than it was 250 million years ago. The area was underwater, lying off the western coast of super continent Pangaea.
“Our coelacanth had a forked tail, indicating it was a fast-moving, aggressive predator, which is very different from the shape and movement of all other coelacanths in the fossil record,” Wendruff said. It is believed this three foot long, fork tailed fish is an off shoot of the lineage that lived almost 250 million years ago. Falling between the first coelacanth fossils from 400 million years ago and the most recent of about 75 million years ago.
Typically these fish are slow moving and chunky, laying in wait for prey to ambush. The newly discovered coelacanth is so different from others it’s been given a new name, Rebellatrix, or “rebel coelacanth.” It’s believed to be a failure in evolution, however, because it does not appear later in the fossil record. “Clearly, some other fish groups with forked tails must have outperformed this coelacanth, as it does not appear later in the fossil record,” Wendruff said, adding one group of fishes that may have outperformed Rebellatrix were sharks, as fossils have been found in the same rocks.
University of Alberta (2012, May 2). Old fish makes new splash: Coelacanth find rewrites history of the ancient fish. ScienceDaily. Retrieved May 10, 2012, from http://www.sciencedaily.com /releases/2012/05/120502133110.htm
Wendruff, A. and M.V.H. Wilson. A fork-tailed coelacanth, Rebellatrix divaricerca, gen. et sp. nov. (Actinistia: Rebellatricidae, fam. nov.), from the Lower Triassic of western Canada. Journal of Vertebrate Paleontology, 2012 (32)3: pp. 499-511