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OH 5 (Olduvai Hominid number 5, also known as ''Zinjanthropus'' or "Nutcracker Man"; colloquially as "Dear Boy"〔Cela-Conde & Ayala, 158; Lewin & Foley, 235; Morell, 183.〕) is a fossilized cranium and the holotype of the species ''Paranthropus boisei''. It was discovered in Olduvai Gorge, Tanzania, by archaeologist-paleontologist Mary Leakey in 1959. Her husband and fellow scientist Louis Leakey initially classified the hominid as ''Zinjanthropus boisei'' and thought that it was an early ancestor of modern humans that lived approximately 2 million years ago. However, this contention was later withdrawn because of its robust australopithecine features and the discovery of ''Homo habilis'' soon thereafter. ==Discovery== Mary and Louis Leakey had conducted excavations in Tanzania since the 1930s, though most such work was postponed due to the outbreak of World War II. They returned in 1951, finding mostly ancient tools and fossils of extinct mammals for the next few years.〔Mary Leakey, ''My Search'', 52–53, 83; Lewin & Foley, 234.〕 On the morning of July 17, 1959, Louis felt ill and stayed at camp while Mary went out to Bed I's Frida Leakey Korongo (''korongo'' is Swahili for gully; this one was named after Louis's ex-wife).〔Bowman-Kruhm, 66; Mary Leakey, ''Excavations'', 227; Morell, 180–181.〕 Sometime around 11:00 a.m., she noticed a piece of bone that "seemed to be part of a skull" which had a "hominid look".〔Mary Leakey, ''My Search'', 75.〕 After dusting some topsoil away and finding "two large teeth set in the curve of a jaw", she drove back to camp exclaiming "I've got him!"〔Morell, 181.〕 They created a pile of stones around the exposed portion of the fossil to protect it from the weather.〔Mary Leakey, ''Excavations'', 227.〕 Active excavation began the following day; they had chosen to wait for photographer Des Bartlett to arrive so that a photographic record of the entire process of removal could be made.〔 A partial cranium was fully unearthed August 6, though it had to be reconstructed from its fragments which were scattered in the scree.〔Cela-Conde & Ayala, 158; Morell, 183–184.〕 Once he had examined the cranium, Louis determined it to be subadult, or adolescent, based on its dentition, and he and Mary began to call it "Dear Boy".〔Cracraft & Donoghue, 524; Deacon, 56; Morell, 183–184.〕 He also believed that it was of a species ancestral to modern humans but a member of the subfamily Australopithecinae.〔Cela-Conde & Ayala, 158; Johanson, Edgar & Brill, 156〕 In describing the fossilized hominid in his journal, Louis initially considered the classification ''Titanohomo mirabilis'' (wonderful Titan-like man),〔Johanson, Edgar & Brill, 156; Morell, 183.〕 but he eventually dubbed their find ''Zinjanthropus boisei'' (East Africa man). ''Zinj'' is an ancient Arabic word for the East African coast; ''anthropus'' refers to the fossil's humanlike characteristics; and ''boisei'' refers to Charles Boise, who had been making financial contributions to the Leakeys' work since 1948.〔Louis Leakey, "A new fossil skull from Olduvai", 491; Morell, 185–186.〕 This classification was eventually revised to ''Paranthropus boisei'', though this remains a matter of contention since the genus ''Paranthropus'' is disputed because of morphological similarities to ''Australopithecus''.〔Bowman-Kruhm, 67; Cela-Conde & Ayala, 158; Cracraft & Donoghue, 524; Deacon, 56.〕 In either case, 5 is the holotype of its species.〔Cela-Conde & Ayala, 158.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「OH 5」の詳細全文を読む スポンサード リンク
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