Lake Natron
The Peninj Mandible(Peninj 1), also called Natron mandible, is the fossilized lower jaw and teeth of an australopithecine specimen, likely that of "Australopithecus boisei" or a similar population. It was discovered in West Lake Natron, in the Arusha Region of Tanzania by Kamoya Kimeu, Glynn Isaac, and Richard Leakey in 1964.