Via New York Times:
... before subsequent discoveries turned up well-preserved hindquarters of Tiktaalik roseae, a transitional species that lived 375 million years ago. New findings, reported Monday in Proceedings of the National Academy of Sciences, challenge the theory that vertebrates did not gain four-limbed mobility until well after they had settled the land.
Five new specimens of Tiktaalik (pronounced tic-TAH-lick) fossils found in the Canadian Arctic reveal that the modification of fins into four limbs actually began as adaptations for life in shallow water, according to a research team led by Neil H. Shubin, an evolutionary biologist at the University of Chicago. The change may have enabled the fish to walk on a lake floor, paddle about and even make brief forays on land, the scientists said. ...
