Paranthropus boisei Temporal range: Pliocene-Pleistocene, 2.3–1.2 Ma PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Hominidae
Genus:	Paranthropus
Species:	P. boisei
Binomial name
†Paranthropus boisei (Mary Leakey, 1959)
synonyms
Zinjanthropus boisei (Louis Leakey, 1959)

Paranthropus boisei or Australopithecus boisei was an early hominin, described as the largest of the Paranthropus genus (robust australopithecines). It lived in Eastern Africa during the Pleistocene epoch from about 2.3 until about 1.2 million years ago.^[1]

  Discovery

First discovered by anthropologist Mary Leakey on July 17, 1959, at Olduvai Gorge, Tanzania, the well-preserved cranium (nicknamed "Nutcracker Man") was dated to 1.75 million years old and had characteristics distinctive of the robust australopithecines. Mary and her husband Louis Leakey classified the find as Zinjanthropus boisei: "Zinj" for the medieval East African region of Zanj, "anthropus" meaning ape or ape-human, and "boisei" for Charles Boise (the anthropologists team’s funder at the time).^[2]

Paranthropus boisei (as the species was eventually categorized) proved to be a treasure especially when the anthropologists' son Richard Leakey considered it to be the first hominin species to use stone tools. Another skull was unearthed in 1969 by Richard at Koobi Fora near the Lake Turkana region, in Kenya.

  Morphology and interpretations

  Paranthropus boisei reconstruction

The brain volume is quite small, about 500 and 550 cm³, not much larger in comparison to Australopithecus afarensis and Australopithecus africanus. The average adult males were larger than females (sexual dimorphism), as was the case in virtually all australopithecine species. Males weighed 49 kg (108 lb) and stood 1.37 m (4 ft 6 in) tall, while females weighed 34 kg (75 lb) and stood 1.24 m (4 ft 1 in) tall.^[1]

It had a skull highly specialized for heavy chewing and several traits seen in modern day gorillas. P. boisei inhabited savannah woodland territories. The back molar teeth were relatively large, with an area over twice as great as is found in modern humans.^[3] The species is sometimes referred to as “Nutcracker Man” because it has the biggest, flattest cheek teeth and the thickest enamel of any known hominin.^[4]

Some argue that the craniodental morphology of this taxon (e.g., large postcanine dentition, thick enamel, robust mandibles, sagittal cresting, flaring zygomatic region) are indicative of a diet of hard or tough foods such as ground tubers, nuts and seeds.^[5] However, research on the molar microwear of P. boisei^[6][7] found a microwear pattern very different than that observed for P. robustus in South Africa which is thought to have fed on hard foods as a "fallback resource^[8]. This work suggests that hard foods were an infrequent part of its diet. The carbon isotope ratios of P. boisei suggest that it had a diet dominated by C4 vegetation.

  Fossils

  Cast of the skull sometimes known as "Nutcracker Man", found by Mary Leakey in 1959, with jaw discovered by Kamoya Kimeu in 1964.

In 1993, A. Amzaye found fossils of P. boisei at Konso, Ethiopia. The partial skull's designation is KGA10-525 and is dated to 1.4 million years old. It is the biggest skull specimen ever found of P. boisei. The oldest specimen of P. boisei was found in Omo, Ethiopia and dates to 2.3 million years old, classified as (L. 74a-21) while the youngest specimen from Olduvai Gorge dates 1.2 million years old, classified as OH 3 and OH 38.

  Other well preserved specimens

• OH 5 Zinjanthropus, "Zinj" or "Nutcrackerman" was the first P. boisei specimen found by Mary Leakey at Olduvai Gorge, Tanzania belonging to an adult male (circa 1.75 mya).

• KNM ER 406 is a small partial cranium discovered by Richard Leakey and H. Mutua in 1969, found at Koobi Fora, Kenya, which displays large zygomatic arches, and a cranial capacity of 510 cm³ (circa 1.7 mya).

• KNM WT 17400 is a partial cranium, with similar characteristics as KNM WT 17000 "Black skull" belonging to Paranthropus aethiopicus, and was found at West Turkana, Kenya (circa 1.7 mya).

  See also

• List of fossil sites (with link directory)
• List of hominina (hominid) fossils (with images)
• Olduwan

  References

  External links

Wikimedia Commons has media related to: Paranthropus boisei

• Archaeology Info
• MNSU
• Paranthropus boisei - The Smithsonian Institution's Human Origins Program
• The first skull of Australopithecus boisei, Gen Suwa et al., letters to nature, Nature, Vol. 389, 2 October 1997
• American Museum of Natural History illustration of P. boisei by Jay Matternes