The new carnivore, named Tawa hallae, stood about 28 inches tall at the hips and was about 6 feet long. It had sharp teeth, a long neck, an even longer tail and short arms with fearsome claws, and it could run on two large feet.This suggests that birds were not necessarily a late evolutionary adaptation to a radically changing environment, but an early form of yet another theropod branch of dinosaur.
It is also the earliest known dinosaur to contain air sacs along its backbone and in its neck and head - a clear sign of its evolutionary relationship to modern birds, said Sterling J. Nesbitt, a researcher at the University of Texas, Austin.
Nesbitt is the lead author of the Science report. He did his undergraduate studies at UC Berkeley with Kevin Padian, the dinosaur expert and curator at the Berkeley Museum of Paleontology.
In addition to the complete Tawa hallae skeleton, the team has found bones of at least five other individuals of Tawa's species, as well as the fossil bones of unrelated carnivorous dinosaurs, plus tens of thousands of other primitive creatures - including the evolutionary ancestors of today's crocodiles, turtles, frogs, lizards, other reptiles and even mammals.
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