Assembling the palate and teeth of Paranthropus. Paranthropus were bipedal hominins that probably descended from the gracile australopithecine hominins (Australopithecus). Paranthropus first appeared roughly 2.7 million years ago. Most species had a brain about 40% the size of a modern human brain. This specimen was discovered by Mary Leaky in 1959 at Olduvai Gorge, Tanzania.