Thursday, July 24, 2014

Scientists: Bird's Ancestors Likely Not Dinosaurs

A fossil found in Inner Mongolia may prove that birds did not evolve from dinosaurs, as many scientists have believed, but from a creature that existed long before.

The Scansoriopteryx, meaning ‘climbing wing,’ could prune the avian evolutionary tree.

Alan Feduccia, biology professor at the University of North Carolina, Chapel Hill, studied the Scansoriopteryx fossil. What he found was something more birdlike than dinosaur-like.

"It’s just not a dinosaur. In other words, there’s not anything about this creature that allows classifying it as a dinosaur," he said.

His study, with co-author Stephen Czerkas and published in The Journal of Ornithology, points out several birdlike features, particularly the foot.

"It has a perching foot, in which the first toe is rotated to the rear, and this is, of course, a perching foot so we know that it was a perching animal,” Feduccia explained.

Even its hip joint, he points out, does not appear to be built for walking like a therapod dinosaur would.

The evidence, Feduccia says, only adds to the idea that birds did not evolve from ground-dwelling dinosaurs, but from tree-climbing ancestors. It's much easier to take to the air by gliding down from trees, like flying squirrels or gliding possums do. Even bats, that actually fly, do not routinely take off from the ground.

“Every group of flying vertebrates, regardless of the order they come from, all evolved from the trees down," he said. "It’s the simplest mechanism.”

Feduccia notes that Scansoriopteryx defines a new class of creatures completely separate from the dinosaurs and expands our understanding of some of the earliest life forms on earth.

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