Paranthropus boisei

Paranthropus boisei or Australopithecus boisei was an early hominin, described as the largest of the genus Paranthropus (robust australopithecines). It lived in Eastern Africa during the Pleistocene epoch from about 2.4 until about 1.4 million years ago. 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 ago and had characteristics distinctive of the robust australopithecines. Mary and her husband Louis Leakey classified the find as Zinjanthropus boisei (which is no longer used): 'Zinj' for the medieval East African region of Zanj, 'anthropus' (from Greek: ἄνθρωπος, anthropos) for 'human being', and 'boisei' for Charles Watson Boise, the anthropologist team’s benefactor. Paranthropus boisei (as the species was eventually categorized, using Robert Broom's 1938 definition of its genus) proved to be a treasure, especially when the anthropologists' son Richard Leakey suggested it was the first hominin species to use stone tools. Bernard Wood of the University of Liverpool, England, posits that tools discovered in Ethiopia and dated to 2.5 million years ago could have been made by Paranthropus boisei. A well-preserved jaw, known as the Peninj Mandible, was found by Richard's colleague Kamoya Kimeu in 1964 in Peninj, Tanzania. Another skull, specimen KNM ER 406, was unearthed in 1969 by Richard at Koobi Fora near Lake Turkana, in Kenya. The brain volume is quite small, about 500 to 550 cm3, not much larger than that of Australopithecus afarensis and Australopithecus africanus or modern-day chimpanzees. In P. boisei the foramen magnum is much shorter than in P. robustus. In addition, the cranial variation of P. boisei is remarkably high. The adult males were larger on average than females (an example of sexual dimorphism), as was the case in virtually all australopithecine species. Males weighed some 49 kg (108 lb) and stood about 1.37 m (4 ft 6 in) tall, while females weighed about 34 kg (75 lb) and were 1.24 m (4 ft 1 in) tall. It had a skull highly specialized for heavy chewing and several traits seen in modern-day gorillas. The molar teeth were very large, with an area over twice that of modern humans. The species is sometimes referred to as 'Nutcracker Man' because it had the biggest, flattest cheek teeth and the thickest enamel of any known hominin. P. boisei had large chewing muscles attached to a pronounced sagittal crest. To accommodate their enormous cheek teeth (four times the size of modern human teeth), P. boisei had a wide face, although the front teeth were much smaller than in similar species. Some argue that the craniodental morphology of this taxon (e.g. large postcanine dentition, thick enamel, robust mandibles, sagittal cresting, flaring zygomatic region) is indicative of a diet of hard or tough foods such as ground tubers, nuts and seeds. However, research on the molar microwear of P. boisei has found a pattern very different from that observed in P. robustus in South Africa, which is thought to have fed on hard foods as a fallback resource. This work suggests that hard foods were an infrequent part of P. boisei's diet. Carbon isotope ratios suggest P. boisei had a diet dominated by C4 vegetation, unlike P. robustus in South Africa. In 1993, A. Amzaye found fossils of P. boisei at Konso, Ethiopia. The partial skull is designated as KGA10-525 and is dated to 1.4 million years ago. 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 ago, classified as (L. 74a-21), while the youngest specimen from Olduvai Gorge dates to 1.2 million years ago and is classified as OH 3 and OH 38. Almost all primates and hominids are or were dietary generalists, meaning that they ate a wide variety of foods and did not depend on a single, specific food source.