antediluvian, antiquated, archaic -- (so extremely old as seeming to belong to an earlier period; "a ramshackle antediluvian tenement"; "antediluvian ideas"; "archaic laws")
archaic, primitive -- (little evolved from or characteristic of an earlier ancestral type; "archaic forms of life"; "primitive mammals"; "the okapi is a short-necked primitive cousin of the giraffe")