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. [ Gr. 'archai^os ancient + pte`ryx wing. ] (Paleon.) A fossil bird, of the Jurassic period, remarkable for having a long tapering tail of many vertebræ with feathers along each side, and jaws armed with teeth, with other reptilian characteristics. [ 1913 Webster ]
(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