Fossil fish re-defines origins of walking
Source: abc.net.au
Fossils of a creature that looked part-fish and part-limbed animal, the precursor to walking land animals, were recently found in northern Canada, according to a new study.The beastie, Tiktaalik roseae, represents the best-known transitional species between fish and land-dwelling animals, according to researchers.
The fossil, described in this week’s edition of Proceedings of the National Academy of Sciences, lived 375 million years ago.
 Color illustration of Tiktaalik swimming and walking in water. |
"Tiktaalik was a combination of primitive and advanced features," says co-author Edward Daeschler, Associate Curator of Vertebrate Zoology at the Academy of Natural Sciences of Drexel University.
While classified as a fish, Tiktaalik looked like a cross between a fish and a crocodile. It could grow to nearly 3 metres in length, and likely spent its days hunting in shallow freshwater environments. It had gills, scales and fins, but also had features associated with terrestrial animals. These included a mobile neck, a robust ribcage and primitive lungs.
Of most interest to the researchers, its large forefins had shoulders, elbows and partial wrists, which allowed it to support itself on ground.
The presence of these limb-like features challenges the theory that such mobile hind appendages developed only after species transitioned to life on land.
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Read the full article at: abc.net.au
