始生代[的]
Archaeozoic \Ar`ch[ae]*o*zo"ic\, a. [Gr. 'archai^os ancient + zw^,on animal.] (Zo["o]l.) Like or belonging to the earliest forms of animal life.
Archaeozoic n : the time from 3,800 million years to 2,500 million years ago; earth's crust formed; unicellular organisms are earliest forms of life [syn: {Archean}, {Archean eon}, {Archean aeon}, {Archeozoic}, {Archeozoic eon}, {Archaeozoic aeon}]