Paranthropus is an extinct genus of robust australopithecines . They probably descended from the gracile australopithecine Australopithecus . The robust australopithecines , members of the extinct hominin genus Paranthropus ( Greek para `` beside '' , Greek anthropos `` human '' ) , were bipedal hominids that probably descended from the gracile australopithecine hominids ( Australopithecus ) .