n. 1. an extinct primitive toothed bird (Archaeopteryx lithographica) of the Upper Jurassic having a long feathered tail and hollow bones; usually considered the most primitive of all known birds. Same as archaeopteryx. Syn. -- archaeopteryx. [ WordNet 1.5 ]
(n) extinct primitive toothed bird of the Jurassic period having a long feathered tail and hollow bones; usually considered the most primitive of all birds, Syn. archeopteryx, Archaeopteryx lithographica