Smart mouth - Chinese fish fossil sheds light on jaw evolution

By Will Dunham WASHINGTON (Reuters) - A bottom-dwelling, mud-grubbing, armoured fish that swam in tropical seas 423 million years ago is fundamentally changing the understanding of the evolution of an indisputably indispensable anatomical feature: the jaw. "Now we know that one branch of placoderms evolved into modern jawed vertebrates," said study co-leader Zhu Min, a paleontologist at Chinese Academy of Sciences' Institute of Vertebrate Paleontology and Paleoanthropology.