Ancient Legged Fish

Doran Teverovsky
Mr. Mathieu
Period 2

Michelle Lograta
January 15, 2013
http://www.gmanetwork.com/news/story/343973/scitech/science/ancient-legged-fish-provides-missing-link-in-limb-evolution

Summary:
   Recently, a new fossil has been found in Canada of a type of fish, about 375 million years old, that had legs, and could possibly walk on land and water. This nine foot long fish also provided challenging to classify because it blurred the line between crocodile and fish. While this fish, named the Tiktaalik roseae, had a similar rib cage and lung structure to a crocodile, it also had gills and scales leading scientists to name it as a fish. This fish has given scientist much more conclusive proof that rear appendages evolved in water then gradually went to land. The massive pelvis of this fish was what gave it away is a walker. The pelvis was open, and was shaped for legs and possibly even a fin as well.

Connection:
    This recent fish find relates to evolution, classification, and phylogeny. Before, we were guessing as to where legs evolved, with this fish, we can much more easily place mammals and fish on the same phylogeny because of this ancestor. Also, this connects to classifying organisms, and how difficult it can be for scientists. Because this animal had such crocidillian, and fish like characteristics, people had to pool all of there resources to decide what to call the animal. This animal is a great example of how one thong leads to another in evolution, and how the slightest advantage, by getting on land first, leads to adaptive radiation in the extreme.