Meganthropus fossils from Java Pleistocene include massive jaws and skulls larger than gorillas. Jaw Sangiran 6 height matches gorilla but peaks at first molar unlike apes. Weidenreich estimated Meganthropus 8 feet tall weighing 400-600 pounds. 2019 tooth study confirms distinct pongine genus not Homo or Pongo. Related most closely to Miocene Lufengpithecus. Fossils dated 1.4-0.9 million years show robust traits beyond H. erectus range. Sangiran 31 cranium has double sagittal crest and 800-1000cc capacity outside H. erectus. Some specimens exhibit tool use like H. erectus. Taxonomy debated as H. erectus subspecies or australopithecine but rejected. Kaifu et al assign to primitive H. erectus conservatively. Tyler argues separate species due to primitiveness and low capacity. Krantz reconstruction dubious as giant H. habilis. Island gigantism links to Gigantopithecus. Paraphyletic assemblage possible from few finds. Pithecanthropus dubius junior synonym. Non-hominin status satisfies mystery ape hypothesis.