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Birds' teeth

作者:宿玷    发布时间:2019-03-07 04:09:05    

A FLEET, predatory dinosaur that lived in Mongolia 80 million years ago had teeth like those of the first birds, not like other dinosaurs. The 1.5-metre-high Bryonosaurus, a member of a group of large-eyed, large-brained dinosaurs called troodonts, had smooth teeth. They resemble those of Archaeopteryx, the first bird, which lived some 150 million years ago. A new analysis of the troodonts’ other bone features makes them appear to be closer relatives of birds than other dinosaurs, says Mark Norell of the American Museum of Natural History in New York (Journal of Vertebrate Paleontology, vol 20, p 7). However,

 

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