![]() Feathers, once thought unique to birds, must have evolved in dinosaurs long before birds developed. The discovery of these new intermediary species, which filled in the spotty fossil record, triggered a change in how paleontologists conceived of the dinosaur-to-bird transition. Though many of these fossils lacked wings, they had a panoply of plumage, from fuzzy bristles to fully articulated quills. In the 1990s, an influx of new dinosaur fossils from China revealed a feathery surprise. The work demonstrates how huge evolutionary changes can result from a series of small evolutionary steps. Adaptations such as these may have paved the way for modern birds’ distinguishing features, namely their ability to fly and their remarkably agile beaks. Not only are birds much smaller than their dinosaur ancestors, they closely resemble dinosaur embryos. And recent research suggests that a few simple change-among them the adoption of a more babylike skull shape into adulthood-likely played essential roles in the final push to bird-hood. Discoveries have shown that bird-specific features like feathers began to emerge long before the evolution of birds, indicating that birds simply adapted a number of pre-existing features to a new use. Only such substantial alterations on a short timescale, the story went, could account for the sudden transformation from a 300-pound theropod to the sparrow-size prehistoric bird Iberomesornis.īut it has become increasingly clear that the story of how dinosaurs begat birds is much more subtle. To explain this miraculous metamorphosis, scientists evoked a theory often referred to as “hopeful monsters.” According to this idea, major evolutionary leaps require large-scale genetic changes that are qualitatively different from the routine modifications within a species. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. If you're enjoying this article, consider supporting our award-winning journalism by subscribing. “Archaeopteryx seemed to emerge fully fledged with the characteristics of modern birds,” said Michael Benton, a paleontologist at the University of Bristol in England. These animals appeared to have acquired their birdlike features - feathers, wings and flight - in just 10 million years, a mere flash in evolutionary time. A velociraptor, for example, had a skull like a coyote’s and a brain roughly the size of a pigeon’s.įor decades, paleontologists’ only fossil link between birds and dinosaurs was archaeopteryx, a hybrid creature with feathered wings but with the teeth and long bony tail of a dinosaur. The theropods most closely related to avians generally weighed between 100 and 500 pounds - giants compared to most modern birds - and they had large snouts, big teeth, and not much between the ears. Modern birds descended from a group of two-legged dinosaurs known as theropods, whose members include the towering Tyrannosaurus rex and the smaller velociraptors. From Quanta Magazine ( find original story here ).
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