Gigantopithecus blacki is only known through fossil teeth and mandibles found in cave sites in Southeast Asia. As the name suggests, these are appreciably larger than those of living gorillas, but the exact size and structure of the rest of the body can only be estimated in the absence of additional findings. Dating methods have shown that G. blacki existed for about a million years, going extinct about 100,000 years ago after having been contemporary with (anatomically) modern humans (Homo sapiens) for tens of thousands of years, and co-existing with H. erectus before the appearance of H. sapiens.
Read more about this topic: Gigantopithecus, Species