Suborder: Aves
Birds
Definition:
Bipedal archosaurs with a unique respiratory system, homeothermy,
modified terminal posterior vertebrae (pygostyle), and feathers. Living
birds lack teeth, though many fossil species were toothed. Birds
include some 10,000 named species, making them the most species-rich
group of terrestrial vertebrates.
Birds
probably arose sometime in the middle Jurassic period some 200 million
years ago. The oldest known fossil of a bird is Archaeopteryx
lithographica from Bavaria. Archaeopteryx dates back some
150 million years. A second species, A. bavaricus was named in
the 1990s, also from Bavaria.
