missing link

missing link
    n 1: hypothetical organism formerly thought to be intermediate
         between apes and human beings [syn: {missing link}, {ape-
         man}]
    

44 Moby Thesaurus words for "missing link":
      Bronze Age man, Hominidae, Iron Age man, Stone Age man, aboriginal,
      aborigine, ancient, antediluvian, anthropoid, ape-man, arrearage,
      autochthon, break, bushman, cave dweller, caveman, defalcation,
      defect, deficiency, deficit, discontinuity, fossil man, gap,
      hiatus, hominid, humanoid, interval, lack, lacuna, man of old,
      need, omission, outage, preadamite, prehistoric man, prehuman,
      primate, primitive, protohuman, shortage, troglodyte, ullage, want,
      wantage