Fertile Crescent :
111-598: Zinj may refer to: Paranthropus boisei , nicknamed "Zinj" for its former name Zinjanthropus boisei Zinj, Bahrain , a suburb of Manama, Bahrain Zinj , alternate spelling of Zanj , a medieval area of the East African coast Zinj - name of the fictional lost city in Michael Crichton's 1980 novel Congo , and its 1995 film adaptation Topics referred to by
222-414: A "place of origin" and that they foraged outward from this home base, returning with high-quality food to share and to be processed. Over the course of the last 30 years, a variety of competing theories about how foraging occurred have been proposed, each one implying certain kinds of social strategy. The available evidence from the distribution of tools and remains is not enough to decide which theories are
333-557: A "portable culture". At the time, this was considered very significant, as portability supported the conclusion that the Oldowan tool-makers were capable of planning for future needs, by creating the tools in a location which was distant from their use. The Swartkrans site is a cave filled with layered fossil-bearing limestone deposits. Oldowan is found in Member 1 Lower Bank at 2.2-1.8 Ma in association with Paranthropus robustus and
444-406: A branch was separated, it could be scraped clean with a scraper, or hollowed with pointed tools. Such uses are attested by characteristic microscopic alterations of edges used to scrape wood. Oldowan tools could also have been used for preparing hides. Hides must be cut by slicing, piercing and scraping them clean of residues. Flakes are most suitable for this purpose. Lawrence Keeley , following in
555-414: A combination of terrestrial walking as well as suspensory behaviour , or was completely bipedal but retained an ape-like upper body condition from some ancestor species due to a lack of selective pressure to lose them. In contrast, the P. robustus hand is not consistent with climbing. The hand of KNM-ER 47000 shows Australopithecus -like anatomy lacking the third metacarpal styloid process (which allows
666-399: A diet of predominantly C4 plants, such as low quality and abrasive grasses and sedges. Thick enamel is consistent with grinding abrasive foods. The microwear patterns in P. robustus have been thoroughly examined, and suggest that the heavy build of the skull was only relevant when eating less desirable fallback foods. A similar scheme may have been in use by P. boisei . Such a strategy
777-507: A fallback or possibly primary food source, and noted that there may be a correlation between high USO abundance and hominin occupation. In this model, P. boisei may have been a generalist feeder with a predilection for USOs, and may have gone extinct due to an aridity trend and a resultant decline in USOs in tandem with increasing competition with baboons and Homo . Like modern chimps and baboons, australopithecines likely foraged for food in
888-426: A faster, apelike growth rate than modern humans largely due to dental development trends. Broadly speaking, the emergence of the first permanent molar in early hominins has been variously estimated anywhere from 2.5 to 4.5 years of age, which all contrast markedly with the modern human average of 5.8 years. The tips of the mesial cusps of the 1st molar (on the side closest to the premolar) of KNM-ER 1820 were at about
999-559: A higher prevalence of flake retouch. Similar tools had already been found in various locations in Europe and Asia for some time, where they were called Chellean and Abbevillian . The oldest tool sites are in the East African Rift system, on the sediments of ancient streams and lakes. This is consistent with what we surmise of the evolution of man . Abbé Breuil was the first recognized archaeologist to go on record to assert
1110-517: A large gap in the hominin fossil record, P. boisei may have persisted until 1 mya. P. boisei changed remarkably little over its nearly one-million-year existence. P. boisei is the most robust of the robust australopithecines, whereas the South African P. robustus is smaller with comparatively more gracile features. The P. boisei skull is heavily built, and features a defined brow ridge , receding forehead, rounded bottom margins of
1221-412: A larger sagittal crest than females (particularly gorillas and orangutans), the crest may be influenced by sexual selection in addition to supporting chewing muscles. Further, the size of the sagittal crest (and the gluteus muscles ) in male western lowland gorillas has been correlated with reproductive success. They extended their interpretation of the crest to the males of Paranthropus species, with
SECTION 10
#17327650111461332-419: A million years, and would fall into the pre-human period, associated with the direct australopithecine ancestors of genus Homo . It is not clear whether the tools of such a "Lomekwian industry" bear any relation to the Oldowan industry. There are articles that address how some Oldowan tools may have been found as stones with naturally occurring shapes that dictate their ideal use, or formed as such. To form
1443-500: 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 also argued that Paranthropus is an invalid grouping and synonymous with Australopithecus , so the species is also often classified as Australopithecus boisei . Robust australopithecines are characterised by heavily built skulls capable of producing high stresses and bite forces , and some of
1554-734: A report of Oldowan artefacts in a secure dating context of 1.9 to 2.4 Ma from Ain Boucherit (Ain Hanech) in Setif . Kanjera South, part of the Kanjera site complex, and Nyayanga are located on the Homa Peninsula . Kanjera South is estimated to around 2 Ma. while Nyayanga is estimated to 2.9 Ma. One of the significant excavations, in the area, is Leakey's expedition in 1932-35. In 1995, Oldowan and Plio-Pleistocene faunal remains surfaced from
1665-522: A sample of 10 P. boisei specimens, brain size varied from 444–545 cc (27.1–33.3 cu in) with an average of 487.5 cc (29.75 cu in). However, the lower-end specimen, Omo L338‐y6, is a juvenile, and many skull specimens have a highly damaged or missing frontal bone which can alter brain volume estimates. The brain volume of australopithecines generally ranged from 400–500 cc (24–31 cu in), and for contemporary Homo 500–900 cc (31–55 cu in). Regarding
1776-456: A scientific designation. In the late 20th century, discovery of the discrepancies in date caused a crisis of definition. Because Abbevillian did not necessarily precede Acheulean and both traditions had flakes and bifaces, it became difficult to differentiate the two. It was in this spirit that many artifacts formerly considered Abbevillian were labeled Acheulean. In consideration of the difficulty, some preferred to name both phases Acheulean. When
1887-422: A single fossil attributed to Homo . The Member I assemblage also includes a shaft of pointed bone polished at the pointed end. Member I contained a high percentage of primate remains compared to other animal remains, which did not fit the hypothesis that H. habilis or P. robustus lived in the cave. C. K. Brain conducted a more detailed study and discovered the cave had been the abode of leopards, who preyed on
1998-405: A small jawbone fragment. In 2015, based on OH 80, American palaeoanthropologist Michael Lague recommended assigning the isolated humerus specimens KNM-ER 739, 1504, 6020 and 1591 from Koobi Fora to P. boisei . In 2020, the first associated hand bones were reported, KNM-ER 47000 (which also includes a nearly complete arm), from Ileret , Kenya. The remains were clearly australopithecine (not of
2109-559: Is a currently obsolescent name for a tool tradition that is increasingly coming to be called Oldowan. The label Abbevillian prevailed until the Leakey family discovered older (yet similar) artifacts at Olduvai Gorge and promoted the African origin of man. Oldowan soon replaced Abbevillian in describing African and Asian lithics. The term Abbevillian is still used but is now restricted to Europe. The label, however, continues to lose popularity as
2220-545: Is also evidence that some species of Paranthropus utilized stone tools. There is presently no evidence to show that Oldowan tools were the sole creation of members of the Homo line or that the ability to produce them was a special characteristic of only our ancestors. Research on tool use by modern wild chimpanzees in West Africa shows there is an operational sequence when chimpanzees use lithic implements to crack nuts. In
2331-500: Is different from Wikidata All article disambiguation pages All disambiguation pages Paranthropus boisei Paranthropus boisei is a species of australopithecine from the Early Pleistocene of East Africa about 2.5 to 1.15 million years ago. The holotype specimen , OH 5 , was discovered by palaeoanthropologist Mary Leakey in 1959 at Olduvai Gorge, Tanzania and described by her husband Louis
SECTION 20
#17327650111462442-420: Is difficult to gauge with accuracy. The jaws are the main argument for monophyly, but such anatomy is strongly influenced by diet and environment, and could in all likelihood have evolved independently in P. boisei and P. robustus . Proponents of monophyly consider P. aethiopicus to be ancestral to the other two species, or closely related to the ancestor. Proponents of paraphyly allocate these three species to
2553-420: Is known from Swartkrans , where a bone shaft with a polished point was discovered in Member (layer) I, dated 1.8–1.5 Ma. The Osteodontokeratic industry , the "bone-tooth-horn" industry hypothesized by Raymond Dart, is less certain. Mary Leakey classified the Oldowan tools as Heavy Duty, Light Duty, Utilized Pieces and Debitage, or waste. Heavy-duty tools are mainly cores. A chopper has an edge on one side. It
2664-452: Is not always clear which is the flake. Later tool-makers clearly identified and reworked flakes. Complaints that artifacts could not be distinguished from naturally fractured stone have helped spark careful studies of Oldowan techniques. These techniques have now been duplicated many times by archaeologists and other knappers, making misidentification of archaeological finds less likely. Use of bone tools by hominins also producing Oldowan tools
2775-457: Is only confidently identified from the skull KNM WT 17000 and a few jaws and isolated teeth, it is debated if P. aethiopicus should be subsumed under P. boisei or if the differences stemming from archaicness justifies species distinction. The terms P. boisei sensu lato ("in the broad sense") and P. boisei sensu stricto ("in the strict sense") can be used to respectively include and exclude P. aethiopicus from P. boisei when discussing
2886-399: Is possible that early hominins simply had a faster dental trajectory and slower life history due to environmental factors, such as early weaning age exhibited in modern indriid lemurs . P. boisei remains have been found predominantly in what were wet, wooded environments, such as wetlands along lakes and rivers, wooded or arid shrublands , and semi-arid woodlands, with the exception of
2997-679: Is similar to that used by modern gorillas , which can sustain themselves entirely on lower quality fallback foods year-round, as opposed to lighter built chimps (and presumably gracile australopithecines) which require steady access to high quality foods. In 1980, anthropologists Tom Hatley and John Kappelman suggested that early hominins ( convergently with bears and pigs ) adapted to eating abrasive and calorie-rich underground storage organs (USOs), such as roots and tubers. Since then, hominin exploitation of USOs has gained more support. In 2005, biological anthropologists Greg Laden and Richard Wrangham proposed that Paranthropus relied on USOs as
3108-511: Is unclear from the archaeological record when the production of Oldowan technologies ended. Other tool-making traditions seem to have supplanted Oldowan technologies by 0.25 Ma. The discovery of stone tools that predate the Oldowan, dated to as early as 3.3 Ma, at the Lomekwi site in Kenya, was announced in 2015. This age pre-dates the current estimates for the age of the genus Homo by half
3219-411: Is unclear how they interacted. To explain why P. boisei was associated with Oldowan tools despite not being the tool maker, Louis Leakey and colleagues, when describing H. habilis in 1964, suggested that one possibility was P. boisei was killed by H. habilis , perhaps as food. However, when describing P. boisei 5 years earlier, he said, "There is no reason whatever, in this case, to believe that
3330-656: Is unifacial if the edge was created by flaking on one face of the core, or bifacial if on two. Discoid tools are roughly circular with a peripheral edge. Polyhedral tools are edged in the shape of a polyhedron. In addition there are spheroidal hammer stones. Light-duty tools are mainly flakes. There are scrapers , awls (with points for boring) and burins (with points for engraving). Some of these functions belong also to heavy-duty tools. For example, there are heavy-duty scrapers. Utilized pieces are tools that began with one purpose in mind but were utilized opportunistically. Because of their use and variation, opportunities lead to
3441-486: The Cradle of Humankind and are largely attributed to P. robustus . In East Africa, a few have been encountered at Olduvai Gorge Beds I–IV, occurring over roughly 1.7 to 0.8 million years ago, and are usually made of limb bones and possibly teeth of large mammals, most notably elephants . The infrequency of such large animals at this site may explain the relative rarity of bone tools. The toolmakers were modifying bone in much
Zinj - Misplaced Pages Continue
3552-535: The Shungura Formation , Ethiopia; Koobi Fora and Chesowanja , Kenya; and Omo and Konso , Ethiopia. Among the notable specimens found include the well preserved skull KNM-ER 406 from Koobi Fora in 1970. In 1997, the first specimen with both the skull and jawbone (and also one of the largest specimens), KGA10-525, was discovered in Konso. In 1999, a jawbone was recovered from Malema, Malawi, extending
3663-610: The crocodile Crocodylus anthropophagus . Oldowan Europe : Africa : Siberia : The Oldowan (or Mode I ) was a widespread stone tool archaeological industry (style) in prehistory . These early tools were simple, usually made by chipping one, or a few, flakes off a stone using another stone. Oldowan tools were used during the Lower Paleolithic period, 2.9 million years ago up until at least 1.7 million years ago (Ma), by ancient Hominins (early humans) across much of Africa. This technological industry
3774-420: The dental alveolus (an earlier stage of development than gum emergence), so, unless either specimen is abnormal, P. robustus may have had a higher tooth-root formation rate. The specimen's 1st molar may have erupted 2–3 months before death, so possibly at 2.7–3.3 years of age. In modern apes (including humans), dental development trajectory is strongly correlated with life history and overall growth rate, but it
3885-502: The dural venous sinuses , in 1983, American neuroanthropologist Dean Falk and anthropologist Glenn Conroy suggested that, unlike A. africanus or modern humans, all Paranthropus (and A. afarensis ) had expanded occipital and marginal (around the foramen magnum ) sinuses, completely supplanting the transverse and sigmoid sinuses . In 1988, Falk and Tobias demonstrated that hominins can have both an occipital/marginal and transverse/sigmoid systems concurrently or on opposite halves of
3996-400: The eye sockets , inflated and concave cheek bones , a thick palate , and a robust and deep jawbone. This is generally interpreted as having allowed P. boisei to resist high stresses while chewing, though the thick palate could instead be a byproduct of facial lengthening. The skull features large rough patches (rugosities) on the cheek and jawbones, and males have pronounced sagittal (on
4107-409: The 3rd molar 340 mm (0.53 sq in). The molars are bunodont , featuring low and rounded cusps . The premolars resemble molars (are molarised), which may indicate P. boisei required an extended chewing surface for processing a lot of food at the same time. The enamel on the cheek teeth are among the thickest of any known ape, which would help resist high stresses while biting. In
4218-623: The Congo). Dart made his now famous joke, "... what would have happened if [the A. africanus specimen] Mrs. Ples had met Dear Boy one dark night." At the time of discovery, there was resistance to erecting completely new genera based on single specimens, and the Congress largely rejected " Zinjanthropus ". In 1960, American anthropologist John Talbot Robinson pointed out that the supposed differences between " Zinjanthropus " and Paranthropus are due to OH 5 being slightly larger, and so recommended
4329-677: The Ethiopian A. garhi as the ancestor of P. aethiopicus instead of A. africanus (assuming Paranthropus is monophyletic, and that P. aethiopicus evolved at a time in East Africa when only A. garhi existed there). A. africanus P. aethiopicus P. boisei P. robustus A. africanus P. robustus P. aethiopicus P. boisei Homo Australopithecus sediba A. garhi P. boisei P. robustus Because P. boisei and P. aethiopicus are both known from East Africa and P. aethiopicus
4440-589: The Homa Peninsula in Kenya and are dated to ~2.9 Ma. The Oldowan tools were associated with Paranthropus teeth and two butchered hippo skeletons. Early Oldowan tools are also known from Gona in Ethiopia (near the Awash River ), and are dated to about 2.6 Ma. The use of tools by apes including chimpanzees and orangutans can be used to argue in favour of tool-use as an ancestral feature of
4551-524: The Leakey family, primarily Mary Leakey , but also her husband Louis and their son, Richard . Mary Leakey organized a typology of Early Pleistocene stone tools, which developed Oldowan tools into three chronological variants, A, B and C. Developed Oldowan B is of particular interest due to changes in morphology that appear to have been driven mostly by the short term availability of a chert resource from 1.65 to 1.53 Ma. The flaking properties of this new resource resulted in considerably more core reduction and
Zinj - Misplaced Pages Continue
4662-461: The apparently specialised adaptations of the skull may have only been used with less desirable fallback foods, allowing P. boisei to inhabit a wider range of habitats than gracile australopithecines. P. boisei may have been able to make Oldowan stone tools and butcher carcasses. P. boisei mainly inhabited wet, wooded environments, and coexisted with H. habilis , H. rudolfensis and H. ergaster / erectus . These were likely preyed upon by
4773-465: The argument of sexual dimorphism, but if the specimen does indeed belong to P. boisei , it would show a limb anatomy quite similar to that of the contemporary H. habilis . Instead, the OH 80 femur, more like H. erectus femora, is quite thick, features a laterally flattened shaft, and indicates similarly arranged gluteal , pectineal and intertrochanteric lines around the hip joint . Nonetheless,
4884-519: The artifacts at sites EG10 and EG12 were composed of trachyte ) indicating a selectivity in the quality of stone used. Recent excavations have yielded tools in association with cut-marked bones, indicating that Oldowan were used in meat-processing or -acquiring activities. The second oldest known Oldowan tool site comes from the Shungura formation of the Omo River basin. This formation documents
4995-602: The artifacts found are classified as Oldowan or KBS Oldowan dated from 1.9–1.7 Ma, Karari (or "advanced Oldowan") dated to 1.6–1.4 Ma, and some early Acheulean at the end of the Karari. Over 200 hominins have been found, including Australopithecus and Homo . In the Nachukui site in West Turkana, around 500 stone tools were found at a site named Naiyena Engol 2, or NY2. The assemblage at NY2 dates back to 1.8–1.7 Ma, around
5106-616: The basis for the new genus and species " Zinjanthropus boisei " on August 15, 1959. The genus name derives from the medieval term for East Africa, " Zanj ", and the specific name was in honour of Charles Watson Boise , the Leakeys' benefactor. He initially considered the name " Titanohomo mirabilis " ("wonderful Titan-like man"). Soon after, Louis presented " Z. " boisei to the 4th Pan-African Congress on Prehistory in Léopoldville, Belgian Congo (now Kinshasa , Democratic Republic of
5217-562: The best meat, and the hominins had only scavenged. The counter view is that while hunting many large animals would be beyond the reach of an individual human, groups could bring down larger game, as pack hunting animals are capable of doing. Moreover, since many animals both hunt and scavenge, it is possible that hominins hunted smaller animals, but were not above driving carnivores from larger kills, as they probably were driven from kills themselves from time to time. A complete catalog of Oldowan sites would be too extensive for listing here. Some of
5328-406: The best proxy for estimating body mass, is missing, but using the shaft, OH 80 weighed about 50 kg (110 lb) assuming humanlike proportions, and 61.7 kg (136 lb) using the proportions of a non-human ape. The ambiguously attributed, presumed female femur KNM-ER 1500 is estimated to have been of an individual about 124 cm (4 ft 1 in) tall which would be consistent with
5439-562: The better-known sites include the following: Sites in the Gona river system in the Hadar region of the Afar triangle , excavated by Helene Roche, J. W. Harris and Sileshi Semaw, yielded some of the oldest known Oldowan assemblages, dating to about 2.6 million years ago. Raw material analysis done by Semaw showed that some assemblages in this region are biased towards a certain material (e.g.: 70% of
5550-575: The central rift of Kenya since the 1970s with excavations by John Gowlett for his PhD. More recently, Oldowan technology has also been discovered in Kilombe Caldera in an unusual high altitude setting. The stone tools are associated with fossils and have been dated to 1.8 Ma, with Acheulian stone tools occurring in overlying levels. The Oldowan industry is named after discoveries made in the Olduvai Gorge of Tanzania in east Africa by
5661-460: The cooler morning and evening instead of in the heat of the day. By the time OH 5 was discovered, the Leakeys had spent 24 years excavating the area for early hominin remains, but had instead recovered mainly other animal remains as well as the Oldowan stone tool industry . Because OH 5 was associated with the tools and processed animal bones, they presumed it was the toolmaker. Attribution of
SECTION 50
#17327650111465772-423: The course of nut cracking, sometimes they will create unintentional flakes. Although the morphology of the chimpanzees' hammer is different from the Oldowan hammer, chimpanzees' ability to use stone tools indicates that the earliest lithic industries were probably not produced by only one kind of hominin species. Findings from fossil evidence and experimental replication of stone-tool users and manufacturers suggest
5883-469: The crest and resultantly larger head (at least in P. boisei ) being used for some kind of display . This contrasts with other primates which flash the typically engorged canines in agonistic display (the canines of Paranthropus are comparatively small). However, it is also possible that male gorillas and orangutans require larger temporalis muscles to achieve a wider gape to better display the canines. Australopithecines are generally considered to have had
5994-619: The edges by removing very small chips so as to straighten and sharpen the edge. Typically but not necessarily the reworking is accomplished by pressure flaking. While the exact hominid is up for debate, it is believed that some of the first Oldowan makers did fall within the Homo line. However, fossil evidence showed evolutionary features for human precision grip capabilities in Australopithecines. This leads to current anthropological thinking in which Oldowan tools were made by late Australopithecus and early Homo . Homo habilis
6105-469: The entire process. The partial cranium was fully unearthed August 6, though it had to be reconstructed from its fragments which were scattered in the scree . Louis published a short summary of the find and context the following week. Louis determined OH 5 to be a subadult or adolescent based on dental development, and he and Mary nicknamed it "Dear Boy". After they reconstructed the skull and jaws, newspapers began referring to it as "Nutcracker Man" due to
6216-498: The existence of Oldowan tools. While his description was for "Chello- Abbevillean " tools, and post-dated Leakey's finds at Olduvai Gorge by at least ten years, his descriptions nonetheless represented the scholarly acceptance of this technology as legitimate. These findings were cited as being from the location of the Vaal River , at Vereeniging , and Breuil noted the distinct absence of a significant number of cores, suggesting
6327-533: The final product. It is not known for sure which hominin species created and used Oldowan tools. Its emergence is often associated with the species Australopithecus garhi and its flourishing with early species of Homo such as H. habilis and H. ergaster . Early Homo erectus appears to inherit Oldowan technology and refines it into the Acheulean industry beginning 1.7 million years ago. The oldest known Oldowan tools have been found at Nyayanga on
6438-413: The footsteps of Sergei Semenov, conducted microscopic studies (with a high-powered optical microscope) on the edges of tools manufactured de novo and used for the originally speculative purposes described above. He found that the marks were characteristic of the use and matched marks on prehistoric tools. Studies of the cut marks on bones using an electron microscope produce a similar result. Abbevillian
6549-671: The forests of Central Africa by a savanna corridor, these East African forests would have promoted high rates of endemism , especially during times of climatic volatility. Australopithecines and early Homo likely preferred cooler conditions than later Homo , as there are no australopithecine sites that were below 1,000 m (3,300 ft) in elevation at the time of deposition. This would mean that, like chimps, they often inhabited areas with an average diurnal temperature of 25 °C (77 °F), dropping to 10 or 5 °C (50 or 41 °F) at night. P. boisei coexisted with H. habilis , H. rudolfensis and H. ergaster / erectus , but it
6660-492: The frequent modification of tools for either labor or forms of signaling has been proposed as a cause for the different shapes of similar tools. Oldowan tools were probably used for many purposes, which have been discovered from observation of modern apes and hunter-gatherers. Nuts and bones are cracked by hitting them with hammer stones on a stone used as an anvil. Battered and pitted stones testify to this possible use. Heavy-duty tools could be used as axes for woodworking. Once
6771-404: The general shape of an Oldowan tool, a roughly spherical hammerstone is struck on the edge, or striking platform , of a suitable core rock to produce a conchoidal fracture with sharp edges useful for various purposes. The process is often called lithic reduction . The chip removed by the blow is the flake . Some of these flakes can be used as tools, provided the aforementioned conditions for
SECTION 60
#17327650111466882-403: The genus Homo ), and at the time, the only australopithecine genera described were Australopithecus by Raymond Dart and Paranthropus (the South African P. robustus ) by Robert Broom , and there were arguments that Paranthropus was synonymous with Australopithecus . Louis believed the skull had a mix of traits from both genera, briefly listing 20 differences, and so used OH 5 as
6993-438: The genus Australopithecus as A. boisei , A. aethiopicus and A. robustus . Before P. boisei was described (and P. robustus was the only member of Paranthropus ), Broom and Robinson continued arguing that P. robustus and A. africanus (the then only known australopithecines) were two distinct lineages. However, remains were not firmly dated, and it was debated if there were indeed multiple hominin lineages or if there
7104-434: The greater surface area would have permitted the processing of larger quantities of food at once. In the upper jaw, the 1st molar averages roughly 250 mm (0.39 sq in), the 2nd molar 320 mm (0.50 sq in), and the 3rd molar 315 mm (0.488 sq in); in the lower jaw, the 1st molar averages roughly 260 mm (0.40 sq in), the 2nd molar 315 mm (0.488 sq in), and
7215-435: The hand to lock into the wrist to exert more pressure), a weak thumb compared to modern humans, and curved phalanges (finger bones) which are typically interpreted as adaptations for climbing. Nonetheless, despite lacking a particularly forceful precision grip like Homo , the hand was still dextrous enough to handle and manufacture simple tools. In 1954, Robinson suggested that the heavily built skull of Paranthropus (at
7326-404: The hominin family tree, and the exact classification of Australopithecus species with each other is quite contentious. For example, if the South African A. sediba (which evolved from A. africanus ) is considered the ancestor or closely related to the ancestor of Homo , then this could allow for A. africanus to be placed more closely related to Homo than to Paranthropus . This would leave
7437-510: The hominin family. Tools made from bone, wood, or other organic materials were therefore in all probability used before the Oldowan. Oldowan stone tools are simply the oldest recognisable tools which have been preserved in the archaeological record. There is a flourishing of Oldowan tools in eastern Africa, spreading to southern Africa, between 2.4 and 1.7 Ma. At 1.7 Ma., the first Acheulean tools appear even as Oldowan assemblages continue to be produced. Both technologies are occasionally found in
7548-680: The hominins, but archaeologists believe that they would be the strongest candidates for tool manufacture. There are no hominins in those layers, but the same layers elsewhere in the Omo valley contain Paranthropus and early Homo fossils. Paranthropus occurs in the preceding layers. In the last layer at 1.4 million years ago is only Homo erectus . Along the Nile River, within the 100-foot terrace, evidence of Chellean or Oldowan cultures has been found. In November 2018 Science published
7659-434: The huge expanse of time and the multiplicity of species associated with possible Oldowan tools, it is difficult to be more precise than this, since it is almost certain that different social groupings were used at different times and in different places. There is also the question of what mix of hunting, gathering and scavenging the tool users employed. Early models focused on the tool users as hunters. The animals butchered by
7770-514: The initial stone are met before modification. Below the point of impact on the core is a characteristic bulb with fine fissures on the fracture surface. The flake evidences ripple marks. The materials of the tools were for the most part quartz , quartzite , basalt , or obsidian , and later flint and chert . Any rock that can hold an edge will do. The main source of these rocks is river cobbles, which provide both hammer stones and striking platforms. The earliest tools were simply split cobbles. It
7881-448: The intertrochanteric line is much more defined in OH 80, the gluteal tuberosity is more towards the midline of the femur, and the mid-shaft in side-view is straighter, which likely reflect some difference in load-bearing capabilities of the leg. Unlike P. robustus , the arm bones of OH 80 are heavily built, and the elbow joint shows similarities to that of modern gibbons and orangutans . This could either indicate that P. boisei used
7992-500: The lack of definitive P. boisei skeletal remains, save for the presumed male OH 80. Based on an approximation of 400 mm (1.3 ft) for the femur before it was broken and using modern humanlike proportions (which is probably an unsafe assumption), OH 80 was about 156.3 cm (5 ft 1.5 in) tall in life. For comparison, modern human men and women in the year 1900 averaged 163 cm (5 ft 4 in) and 152.7 cm (5.01 ft), respectively. The femoral head ,
8103-604: The large back teeth and jaws which gave it a resemblance to vintage nutcrackers . South African palaeoanthropologist Phillip Tobias , a colleague of the Leakeys, has also received attribution for this nickname. The cranium was taken to Kenya after its discovery and was there until January 1965 when it was placed on display in the Hall of Man at the National Museum of Tanzania in Dar es Salaam. Louis preliminarily supposed OH 5
8214-554: The large carnivores of the time, including big cats , crocodiles and hyenas . Palaeoanthropologists Mary and Louis Leakey had conducted excavations in Tanzania since the 1930s, though work was postponed with the start of World War II . They returned in 1951, finding mostly ancient tools and fossils of extinct mammals for the next few years. In 1955, they unearthed a hominin baby canine and large molar tooth in Olduvai Gorge , catalogue ID Olduvai Hominin (OH) 3. On
8325-502: The large number of bones at many sites, too large to be the work of one individual, and all of the scatter patterns implying many different individuals. Since modern primates in Africa have fluid boundaries between groups, as individuals enter, become the focus of bands, and others leave, it is also probable that the tools we find are the result of many overlapping groups working the same territories, and perhaps competing over them. Because of
8436-587: The largest molars with the thickest enamel of any known ape. P. boisei is the most robust of this group. Brain size was about 450–550 cc (27–34 cu in), similar to other australopithecines. Some skulls are markedly smaller than others, which is taken as evidence of sexual dimorphism where females are much smaller than males, though body size is difficult to estimate given only one specimen, OH 80, definitely provides any bodily elements. The presumed male OH 80 may have been 156 cm (5 ft 1 in) tall and 61.7 kg (136 lb) in weight, and
8547-646: The lineage as a whole. P. aethiopicus is the earliest member of the genus, with the oldest remains, from the Ethiopian Omo Kibish Formation , dated to 2.6 million years ago (mya) at the end of the Pliocene . It is possible that P. aethiopicus evolved even earlier, up to 3.3 mya, on the expansive Kenyan floodplains of the time. The oldest P. boisei remains date to about 2.3 mya from Malema. The youngest record of P. boisei comes Olduvai Gorge (OH 80) about 1.34 mya; however, due
8658-447: The midline) and temporonuchal (on the back) crests, which indicate a massive masseter muscle (used in biting down) placed near the front of the head (increasing mechanical advantage ). This is typically considered to be evidence of a high bite force . The incisors and canines are reduced, which would hinder biting off chunks of large food pieces. In contrast, the cheek teeth of both sexes are enormous ( postcanine megadontia ), and
8769-448: The morning of July 17, 1959, Louis felt ill and stayed at camp while Mary went out to Bed I's Frida Leakey Gully. Sometime around 11:00 AM, she noticed what appeared to be a portion of a skull poking out of the ground, OH 5. The dig team created a pile of stones around the exposed portion to protect it from further weathering. Active excavation began the following day; they had chosen to wait for photographer Des Bartlett to document
8880-400: The most probable. However, three main groups of theories predominate. Each group of models implies different grouping and social strategies, from the relative altruism of central base models to the relatively disjointed search models. (See also central foraging theory and Lewis Binford .) Hominins probably lived in social groups that had contact with others. This conclusion is supported by
8991-549: The nickname "Nutcracker Man". However, in 1981, English anthropologist Alan Walker found that the microwearing patterns on the molars were inconsistent with a diet high in hard foods, and were effectively indistinguishable from the pattern seen in the molars of fruit-eating ( frugivorous ) mandrills , chimpanzees and orangutans . The microwearing on P. boisei molars is different from that on P. robustus molars, and indicates that P. boisei , unlike P. robustus , very rarely ever ate hard foods. Carbon isotope analyses report
9102-742: The number of known specimens to be flimsy. In 1981, Martin applied equations formulated by ecologists Alton S. Harestad and Fred L. Bunnel in 1979 to estimate the home range and population density of large mammals based on weight and diet, and, using a weight of 52.4 kg (116 lb), he got: 130 ha (320 acres) and 0.769 individual per square kilometre if herbivorous; 1,295 ha (3,200 acres) and 0.077 individual if omnivorous; and 287,819 ha (711,220 acres) and 0.0004 individual if carnivorous. For comparison, he calculated 953 ha (2,350 acres) and 0.104 individual per square kilometre for omnivorous, 37.5-kilogram (83 lb) chimps. A 2017 study postulated that, because male non-human great apes have
9213-494: The parietal branch could originate from either the anterior or posterior branches, sometimes both in a single specimen on opposite sides of the skull as in KNM-ER 23000 and OH 5. The wide range of size variation in skull specimens seems to indicate a great degree of sexual dimorphism with males being notably bigger than females. However, it is difficult to predict with accuracy the true dimensions of living males and females due to
9324-421: The peak of the Oldowan period. At the site, freehand flaking was observed to be the most common type of technique for making these tools. A common theme among sites in West Turkana is the high percentage of small flake tools gathered in the assemblages. However, NY2 seems to lack many of these tools, indicating a low productivity rate of flakes. Acheulian stone tools have been known about at Kilombe Main site in
9435-429: The presence of physical characteristics of hand morphology for precise stone tool making. The makers of Oldowan tools were mainly right-handed. " Handedness " ( lateralization ) had thus already evolved, though it is not clear how related to modern lateralization it was, since other animals show handedness as well. In the mid-1970s, Glynn Isaac touched off a debate by proposing that human ancestors of this period had
9546-495: The presumed female KNM-ER 1500 124 cm (4 ft 1 in) tall (though its species designation is unclear). The arm and hand bones of OH 80 and KNM-ER 47000 suggest P. boisei was arboreal to a degree. P. boisei was originally believed to have been a specialist species of hard foods, such as nuts, due to its heavily built skull, but it was more likely a generalist feeder of predominantly abrasive C4 plants, such as grasses or underground storage organs . Like gorillas ,
9657-455: The problematic nature of assuming use from stone artefacts. An example is Isaac et al.'s tri-modal categories of "Flaked Pieces" (cores/choppers), "Detached Pieces" (flakes and fragments), "Pounded Pieces" (cobbles utilized as hammerstones, etc.) and "Unmodified Pieces" (manuports, stones transported to sites). Oldowan tools are sometimes called "pebble tools", so named because the blanks chosen for their production already resemble, in pebble form,
9768-886: The same areas, dating to the same time periods. This realisation required a rethinking of old cultural sequences in which the more "advanced" Acheulean was supposed to have succeeded the Oldowan. The different traditions may have been used by different species of hominins living in the same area, or multiple techniques may have been used by an individual species in response to different circumstances. Sometime before 1.8 Ma Homo erectus had spread outside of Africa, reaching as far east as Java by 1.8 Ma and in Northern China by 1.66 Ma. In these newly colonised areas, no Acheulean assemblages have been found. In China, only "Mode 1" Oldowan assemblages were produced, while in Indonesia stone tools from this age are unknown. By 1.8 Ma early Homo
9879-401: The same level as the cervix (where the enamel meets the cementum ) of its non-permanent 2nd premolar. In baboons, this stage occurs when the 1st molar is about to erupt from the gums. The tooth root is about 5 mm (0.20 in), which is similar to most other hominins at this stage. In contrast, the root of the P. robustus specimen SK 62 was 6 mm (0.24 in) when emerging through
9990-444: The same population density as other large mammals, which would equate to 0.006–1.7 individuals per square kilometre (0.4 square mile). Alternatively, by multiplying the density of either bovids, elephants, or hippos by the percentage of hominin remains out of total mammal remains found at the formation, Boaz estimated a density of 0.001–2.58 individuals per square kilometre. Biologist Robert A. Martin considered population models based on
10101-405: The same term [REDACTED] This disambiguation page lists articles associated with the title Zinj . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Zinj&oldid=1110991453 " Category : Disambiguation pages Hidden categories: Short description
10212-596: The same way as they did with stone. Though the Olduvan bone tools are normally ascribed to H. ergaster / erectus , the presence of both P. boisei and H. habilis obfuscates attribution. In 1979, American biological anthropologist Noel T. Boaz noticed that the relative proportions between large mammal families at the Shungura Formation are quite similar to the proportion in modern-day across sub-Saharan Africa. Boaz believed that hominins would have had about
10323-616: The savanna-dominated Malawian Chiwondo Beds . Its abundance likely increased during precession -driven periods of relative humidity while being more rare during intervals of aridity. During the Pleistocene, there seems to have been coastal and montane forests in Eastern Africa. More expansive river valleys–namely the Omo River Valley–may have served as important refuges for forest-dwelling creatures. Being cut off from
10434-626: The sediments of the Plio-Pleistocene and provides a record of the hominins that lived there. Lithic assemblages have been classified as Oldowan in members E and F in the lower Omo basin. Although there have been lithic assemblages found in multiple sites in these areas, only the Omo sites 57 and 123 in member F are accepted as hominin lithic remains. The assemblages at Omo sites 71 and 84 in member E do not show evidence of hominin modification and are therefore classified as natural assemblages. The tools are never found in direct association with
10545-411: The site. and in 2015 excavations led to the discovery of the earliest Oldowan stone tool technology in association with Paranthropus fossils and butchered hippo remains from Nyayanga. The numerous Koobi Fora sites on the east side of Lake Turkana are now part of Sibiloi National Park . Sites were initially excavated by Richard Leakey, Meave Leakey , Jack Harris, Glynn Isaac and others. Currently
10656-432: The skull [OH 5] represents the victim of a cannibalistic feast by some hypothetical more advanced type of man." OH 80 seems to have been eaten by a big cat. The leg OH 35, which either belongs to P. boisei or H. habilis , shows evidence of leopard predation. Other likely Oldowan predators of great apes include the hunting hyena Chasmaporthetes nitidula , the sabertoothed cats Dinofelis and Megantereon , and
10767-413: The skull, such as with the P. boisei specimen KNM-ER 23000. In 1983, French anthropologist Roger Saban stated that the parietal branch of the middle meningeal artery originated from the posterior branch in P. boisei and P. robustus instead of the anterior branch as in earlier hominins, and considered this a derived characteristic due to increased brain capacity. It has since been demonstrated that
10878-598: The species be reclassified as P. boisei . Louis rejected Robinson's proposal. Following this, it was debated if P. boisei was simply an East African variant of P. robustus until 1967 when South African palaeoanthropologist Phillip V. Tobias gave a far more detailed description of OH 5 in a monograph (edited by Louis). Tobias and Louis still retained " Zinjanthropus ", but recommended demoting it to subgenus level as Australopithecus ("Zinjanthropus") boisei , considering Paranthropus to be synonymous with Australopithecus . Synonymising Paranthropus with Australopithecus
10989-415: The species' southernmost range over 2,000 km (1,200 mi) from Olduvai Gorge. The first definitive bodily elements of P. boisei associated with facial elements, OH 80 (isolated teeth with an arm and a leg), were discovered in 2013. Previously, body remains lacking unambiguous diagnostic skull elements had been dubiously assigned to the species, namely the partial skeleton KNM-ER 1500 associated with
11100-592: The term Mode 1 tools to designate pebble tool industries (including Oldowan), with Mode 2 designating bifacially worked tools (including Acheulean handaxes), Mode 3 designating prepared-core tools, and so forth. Classification of Oldowan tools is still somewhat contentious. Mary Leakey was the first to create a system to classify Oldowan assemblages , and built her system based on prescribed use. The system included choppers , scrapers , and pounders. However, more recent classifications of Oldowan assemblages have been made that focus primarily on manufacture due to
11211-536: The time only including P. robustus ) was indicative of a specialist diet specifically adapted for processing a narrow band of foods. Because of this, the predominant model of Paranthropus extinction for the latter half of the 20th century was that it was unable to adapt to the volatile climate of the Pleistocene , unlike the much more adaptable Homo . It was also once thought P. boisei cracked open nuts and similar hard foods with its powerful teeth, giving OH 5
11322-491: The tools include waterbuck , hartebeest , springbok , pig and zebra . However, the disposition of the bones allows some question about hominin methods of obtaining meat. That they were omnivores is unquestioned, as the digging implement and the probable use of hammer stones to smash nuts indicate. Lewis Binford first noticed that the bones at Olduvai contained a disproportionately high incidence of extremities, which are low in food substance. He concluded other predators had taken
11433-509: The tools was promptly switched to the bigger-brained H. habilis upon its description in 1964. In 2013, OH 80 was found associated with a mass of Oldowan stone tools and animal bones bearing evidence of butchery. This could potentially indicate P. boisei was manufacturing this industry and ate meat to some degree. Additionally, the Early Stone Age of Africa coincides with simple bone tools . In South Africa, these are unearthed in
11544-446: The topic of Abbevillian came up, it was simply put down as a phase of Acheulean. Whatever was from Africa was Oldowan, and whatever from Europe, Acheulean. The solution to the definition problem is to define the types in terms of complexity. Simply struck tools are Oldowan. Retouched, or reworked tools are Acheulean. Retouching is a second working of the artifact. The manufacturer first creates an Oldowan tool. Then he reworks or retouches
11655-526: Was about half a million years old, but in 1965, American geologists Garniss Curtis and Jack Evernden dated OH 5 to 1.75 million years ago using potassium–argon dating of anortoclase crystals from an overlying tuff (volcanic ash) bed. Such an application of geochronology was unprecedented at the time. The first identified jawbone, Peninj 1 , was discovered Lake Natron just north of Olduvai Gorge in 1964. Especially from 1966 to 1975, several more specimens revealing facial elements were reported from
11766-586: Was first suggested by anthropologists Sherwood Washburn and Bruce D. Patterson in 1951, who recommended limiting hominin genera to only Australopithecus and Homo . The genus Paranthropus (otherwise known as "robust australopithecines") typically includes P. boisei , P. aethiopicus and P. robustus . It is debated if Paranthropus is a valid natural grouping ( monophyletic ) or an invalid grouping of similar-looking hominins ( paraphyletic ). Because skeletal elements are so limited in these species, their affinities with each other and to other australopithecines
11877-606: Was followed by the more sophisticated Acheulean industry (two sites associated with Homo erectus at Gona in the Afar Region of Ethiopia dating from 1.5 and 1.26 million years ago have both Oldowan and Acheulean tools ). The term Oldowan is taken from the site of Olduvai Gorge in Tanzania , where the first Oldowan stone tools were discovered by the archaeologist Louis Leakey in the 1930s. However, some contemporary archaeologists and palaeoanthropologists prefer to use
11988-608: Was instead the last common ancestor between Homo and Paranthropus , and A. africanus was the earliest member of the Paranthropus lineage or at least was ancestral to P. robustus , because A. africanus inhabited South Africa before P. robustus , and A. afarensis was at the time the oldest-known hominin species at roughly 3.5 million years old. Now, the earliest known South African australopithecine (" Little Foot ") dates to 3.67 million years ago, contemporaneous with A. afarensis . Such arguments are based on how one draws
12099-416: Was named "skillful" because it was considered the earliest tool-using human ancestor. Indeed, the genus Homo was in origin intended to separate tool-using species from their tool-less predecessors, hence the name of Australopithecus garhi , garhi meaning "surprise", a tool-using Australopithecine discovered in 1996 and described as the "missing link" between the genera Australopithecus and Homo . There
12210-510: Was only 1 leading to humans. In 1975, the P. boisei skull KNM-ER 406 was demonstrated to have been contemporaneous with the H. ergaster / erectus skull KNM ER 3733 , which is generally taken to show that Paranthropus was a sister taxon to Homo , both developing from some Australopithecus species, which at the time only included A. africanus . In 1979, a year after describing A. afarensis from East Africa, anthropologists Donald Johanson and Tim D. White suggested that A. afarensis
12321-607: Was present in Europe, as shown by the discovery of fossil remains and Oldowan tools in Dmanisi , Georgia. Remains of their activities have also been excavated in Spain at sites in the Guadix-Baza basin and near Atapuerca . Most early European sites yield "Mode 1" or Oldowan assemblages. The earliest Acheulean sites in Europe only appear around 0.5 Ma. In addition, the Acheulean tradition does not seem to spread to Eastern Asia. It
#145854