anatomy, each type distinguished by attributes of size or proportionality that indicate more or less aptitude and capacity for flying: Sinosauropteryx, Velociraptor, Unenlagia, Protarchaeopteryx, Caudipteryx, Archaeopteryx, Eoalulavis. The fully evolved modern birds are to be distinguished from dino-bird types by "shortened tailbones and broad wing surfaces" (Chang, 1998).
The terms of the dino-bird debate are as it were evolving with all deliberate speed, as the fossil evidence continues to accumulate. The Archaeopteryx, for example, could not fly any more than modern-day penguins can. Norell (2001) refers to the "feathery appendages" of Caudipteryx, Protarchaeopteryx, Beipaosaurus, and Sinornithosaurus, none of which could fly. But if the hypothesis is valid at all, flight is not the determining factor of evolutionary relation
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