"This bird was more advanced than Archaeopteryx in that it had a beak but was less advanced in that it had two small openings in the rear of its skull very similar to the reptile progenitors of birds," he said. "This is a mosaic pattern we see very much in vertebrate evolution - in other words, various lineages showing both primitive and advanced features at the same time. What this really shows is that early bird evolution was not linear, as many people have depicted it, but rather a far more complicated 'bush' with many extinct lines."
Neither of the two cousin species likely were ancestors of modern birds, Feduccia said. Instead, they were side "twigs" that disappeared from their family tree -- or bush -- millions of years ago.
Males of both species bore two long tail plumes indicating the sexes differed significantly from each other. Like its cousin, the new bird C. dui also grew asymmetric wing feathers characteristic of all modern flying birds. Ostriches and other birds that can't fly well sprout nearly symmetric feathers incapable of creating an airfoil and hence lift.
"These birds also have highly curved foot claws and reversed big toes showing they were clearly tree-dwelling creatures," the scientist said. "Together, these and other characteristics -- and the fact that the birds lived in complex social colonies - show that they were pretty well developed.
"It seems to us that this was a tree-dwelling bird, not an earth-bound, feathered dinosaur as people advocating a dinosaur origin of birds have said."
In 1979, Feduccia made international news by publishing a paper proving that the oldest known bird, Archaeopteryx, could fly because its wing feathers were asymmetric. Barbs on one side of its wing feather quills clearly grew longer than barbs on the other side.
"Some other scientists had speculated that Confusciu
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Contact: David Williamson
David_Williamson@unc.edu
919-962-8596
University of North Carolina at Chapel Hill
16-Jun-1999