Until very recently, none of the known great apes could lay claim to a possible fossil ancestor, but four huge fossilized lower jaws and hundreds of teeth from a giant ape that could be a sasquatch ancestor have been on record for many years.
Designated Gigantopithecus blacki, these giant apes were living in southern China at least until 100,000 years ago, and an older jawbone found in India proves that they existed over a large area and for a very long time. There is no evidence that they spread to North America, but other animals did, and there is no apparent reason why they could not have done the same.
Dr. Grover Krantz reconstructed the complete skull of a Gigantopithecus blacki based on the creatures' lower jaw. A direct comparison with a human skull and a gorilla skull confirms that the "Giganto" was very large.
Whether Gigantopithecus walked upright or on all fours will probably never be certain unless other bones are found. All that the jaws indicate is that an ape of sufficient size to match sasquatch descriptions did exist in relatively recent times, and not too far from North America. Living in parts of North America would have required adapting to life in a much colder climate, but here the creatures' huge size would have been a significant advantage.
Source: Sasquatch Canada