Vertebrate jaw design locked 400 million years ago
Wednesday, July 6, 2011 - 12:31
in Paleontology & Archaeology
More than 99 per cent of modern vertebrates (animals with a backbone, including humans) have jaws, yet 420 million years ago, jawless, toothless armour-plated fishes dominated the seas, lakes, and rivers. There were no vertebrates yet on land and the recently evolved jawed fishes were minor players in this alien world, some sporting unusual jaw shapes and structures that bear little physical resemblance to modern animals.