Paranthropus boisei is a species of australopithecine from the Early Pleistocene of East Africa about 2.3 to 1.34 or 1 million years ago. The holotype specimen, OH 5, was discovered by palaeoanthropologist Mary Leakey in 1959, and described by her husband Louis a month later. It was originally placed into its own genus as "Zinjanthropus boisei", but is now relegated to "Paranthropus" along with other robust australopithecines. However, it is argued that "Paranthropus" is an invalid grouping and synonymous with "Australopithecus", so the species is also often classified as Australopithecus boisei.