"Through consideration of these diverse dating methods and focusing on clades [groups] of birds where relationships are known well, we find corroboration for the Cretaceous origin of most lineages of birds," he said. Brown still supports the "rock record" evidence that birds likely descended from two-footed, carnivorous dinosaurs. The ability to fly, in part, may have saved them from extinction when dinosaurs bit the dust. "The warm-bloodedness of birds, accompanied with their ability to disperse and fly from difficult areas may have been partly responsible for their survival," he explained. Marcel van Tuinen, assistant professor of biology and marine biology at the University of North Carolina at Wilmington, is both a rock and clock expert for bird origins. Van Tuinen told Discovery News that he agrees "with the general timescale" that's been proposed. "My own work continues to show similar ages for the origin and ordinal diversification of modern birds," van Tuinen explained. He added that, in addition to shedding light on the earliest avians, the genetic data also supports "a tightening of the fossil gap" in the more recent history of modern birds, since ancient bird bones may not always reveal the full picture of the bird family tree.
Jennifer Viegas' blog: Born Animal Wikipedia: Antarctica bird fossil |
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