Communications, the Beijing team describes two skeletons of a species they call Archaeornithura meemannae. (Archaeornithura means “ancient ornithuromorph,” and meemannae is in honor of Chinese paleontologist Meemann Chang.) Each exquisitely preserved specimen has the telltale traits of a modern bird: fan-shaped tail feathers, highly fused bones at the ends By Michael Balter living birds. Relatively poor fliers, the opof the wings, and the U-shaped wishbone posite birds also typically had teeth and familiar to anyone who has carved a roast ut yourself on the planet 130 million clawed wings. They thrived for millions of chicken. The fossils even have a small proyears ago. Most of the animals, from years, but vanished along with their dinojection on the front edge of their wings— horned dinosaurs to swimming plesaur relatives in the mass extinction at the known to boost maneuverability during siosaurs, would be deeply alien, not end of the Cretaceous. flight—that is remarkably similar to that of to say terrifying. But rising from the Meanwhile, the lineage of modern birds today’s birds. wetlands and winging across the sky evolved “huge chest muscles and wings Furthermore, Archaeornithura had long were birds startlingly like today’s. That’s comprised of many different types of feathlegs and feet apparently adapted to wadthe message from two bird skeletons— ers layered over each other”—features esing in water, similar to those of today’s plospectacularly preserved with feathers and sential to high-powered flight, Brusatte vers, suggesting that modern birds arose all—reported this week. explains. Their bone structure also sugin aquatic habitats. Finding such a modThe 130-million-year-old fossils of wadgests that they grew much faster than the ern bird, already specialized for wading, ing birds, found in northeast China by a opposite birds. But researchers did not suggests that millions of years of aquatic team led by paleontologists Min Wang and know when those features emerged. They evolution took place even before A. meeZhonghe Zhou of the Institute of Vertehad found some excellent specimens of the mannae came on the scene, Zhou explains. brate Paleontology and Paleoanthropology earliest birds, such as Germany’s famed He suggests that while the opposite birds in Beijing, push back the lineage that led 150-million-year-old Archaeopteryx, as well found safety in the trees, life in more open, to today’s birds by at least 5 million years as stunning later fossils from northeastern aquatic spaces may have given the ornithuand make it almost certain that its origin China (Science, 15 March 2013, p. 1261). But romorphs “more choices of high protein was much older still. The fossils’ speciala yawning gap remained between Archaefood” and favored their evolution into ized anatomy suggests that key factors in opteryx and other fossils, most of which swift fliers so they could avoid the danger birds’ long-term success, such as expert were opposite birds, Chiappe says. of predators. All this evolution must have flying ability and rapid growth rates, arose The new fossils help fill the gap in time happened after Archaeopteryx but before surprisingly early in avian evolution. and also in anatomy. Writing in Nature 130 million years ago. “New bird fossils seem to come The fossils reveal the origins of out every week now, and they the features that, tens of millions are revolutionizing our underof years later, may have allowed standing of bird evolution. But modern birds to survive the Creof all the new specimens, this is taceous extinction when other one of the most important found birds did not, Zhou and Wang say. over the last decade,” says paleonNo one is sure just what conditologist Stephen Brusatte of the tions prevailed in the postasteroid University of Edinburgh in the apocalypse, but Wang speculates United Kingdom. Not only does that the fast growth rates of modthe bird look nearly modern, but ern birds, which let them reach it was also apparently a water adulthood faster and spend less dweller, showing that “ancient time dependent on their parents, birds became specialized in their may have given them an advanrespective habits” very early, says tage. Skilled flight may also have paleontologist Luis Chiappe of been a boon. the Natural History Museum of But this idea is “too simplisLos Angeles County in California. tic,” counters Sankar Chatterjee, Birds were born about a paleontologist at Texas Tech 150 million years ago, when a University in Lubbock, because group of small meat-eating dinomany ornithuromorphs vanished saurs spread their feathered wings during the extinction, too. Neverand took to the skies. They soon theless, Brusatte argues, “from split into two distinct groups: the the ashes of that extinction, a lineage that led to modern birds, few groups of more sophisticated called the ornithuromorphs, and birds, with better flight abilities the so-called opposite birds, or and perhaps faster growth rates, enantiornithines, whose shoulder were able to survive.” Those key ball-and-socket joints connected This 130-million-year-old bird, the oldest known member of the line that led traits, the new fossils show, arose in an inverse way from those of to modern birds, had feathers suited for skillful flight. near the dawn of bird evolution. ■ PALEONTOLOGY

When modern birds took flight




8 MAY 2015 • VOL 348 ISSUE 6235

Published by AAAS


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Feathered fossils from China show that modern birds could fly and wade earlier than expected

Paleontology. When modern birds took flight.

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