90-474: KNM-WT 17000 (also known as " The Black Skull ") is a fossilized adult skull of the species Paranthropus aethiopicus . It was discovered in West Turkana , Kenya by Alan Walker in 1985. Estimated to be 2.5 million years old, the fossil is an adult with an estimated cranial capacity of 410 cc. The fossil's characteristics include a robust build with a prominent sagittal crest . Its distinct coloration
180-547: A genetic susceptibility for pitting enamel hypoplasia on the teeth, and seems to have had a dental cavity rate similar to non-agricultural modern humans. The species is thought to have exhibited marked sexual dimorphism , with males substantially larger and more robust than females. Based on 3 specimens, males may have been 132 cm (4 ft 4 in) tall and females 110 cm (3 ft 7 in). Based on 4 specimens, males averaged 40 kg (88 lb) in weight and females 30 kg (66 lb). The brain volume of
270-498: A different individual, KNM-WT 16005, was also discovered. They clearly belonged to a robust australopithecine . By this point in time, much younger robust australopithecines had been reported from South Africa ( robustus ) and East Africa ( boisei ), and been variously assigned to either Australopithecus or a unique genus Paranthropus . Walker and Leakey assigned KNM WT 17000 to the boisei clade . They noted several anatomical differences, but were unsure if this stemmed from
360-532: A height of 140–150 cm (4 ft 7 in – 4 ft 11 in) and a weight of 68–91 kg (150–201 lb). Consequently, Robinson had described its locomotory habits as, "a compromise between erectness and facility for quadrupedal climbing." In contrast, he estimated A. africanus (which he called " H. " africanus ) to have been 1.2–1.4 m (4–4.5 ft) tall and 18–27 kg (40–60 lb) in weight, and to have also been completely bipedal. Robinson's estimation of P. robustus size
450-473: A high proportion of C 4 savanna plants . In addition, it may have also eaten fruits, underground storage organs (such as roots and tubers), and perhaps honey and termites . P. robustus may have used bones as tools to extract and process food. It is unclear if P. robustus lived in a harem society like gorillas or a multi-male society like baboons . P. robustus society may have been patrilocal , with adult females more likely to leave
540-608: A large quantity of food at the same time. He also found that microwearing on 20 P. boisei molar specimens were indistinguishable from patterning recorded in mandrills , chimps, and orangutans. Despite subsequent arguments that Paranthropus were not specialist feeders, the predominant consensus in favour of Robinson's initial model did not change for the remainder of the 20th century. In 2004, in their review of Paranthropus dietary literature, anthropologists Bernard Wood and David Strait concluded that Paranthropus were most definitely generalist feeders, and that P. robustus
630-577: A little smaller than those of the Peninj mandible, and the second molar a bit bigger. The KNM-WT 16005 jawbone is smaller than what KNM WT 17000 would have had. Many of these P. aethiopicus features are shared with the early A. afarensis , further reiterating the species' archaicness. In general, Paranthropus are thought to have been generalist feeders, with the heavily built skull becoming important when chewing less desirable, lower quality foods in times of famine. Unlike P. boisei which generally
720-497: A member of the human lineage, which "paranthropines" lacked. With the popularisation of cladistics by the late 1970s to 1980s, and better resolution on how Miocene apes relate to later apes, Gigantopithecus was entirely removed from Homininae , and is now placed in the subfamily Ponginae with orangutans. In 1959, another and much more robust australopithecine was discovered in East Africa, P. boisei , and in 1975,
810-592: A non-human ape. In 1972, Robinson suggested including Gigantopithecus in "Paranthropinae", with the Miocene Pakistani " G. bilaspurensis " (now Indopithecus ) as the ancestor of Paranthropus and the Chinese G. blacki . He also believed that they both had a massive build. In contrast, he reported a very small build for A. africanus (which he referred to as " Homo " africanus ) and speculated it had some cultural and hunting abilities, being
900-442: A single specimen on opposite sides of the skull. Regarding the dural venous sinuses , in 1983, 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 . They suggested the setup would have increased blood flow to
990-485: A toothless mandible (Omo 18) from the Shungura Formation , Ethiopia. The name aethiopicus refers to Ethiopia. In 1976, American anthropologist Francis Clark Howell and Coppens reclassified it as A. africanus . In 1985, the skull KNM WT 17000 dating to 2.5 million years ago was reported from Koobi Fora , Lake Turkana , Kenya, by anthropologists Alan Walker and Richard Leakey . A partial jawbone from
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#17327655142731080-410: A wider iliac blade and smaller acetabulum and hip joint. Like modern humans, the ilium of P. robustus features development of the surface and thickening of the posterior superior iliac spine , which are important in stabilising the sacrum , and indicates lumbar lordosis (curvature of the lumbar vertebrae) and thus bipedalism. The anatomy of the sacrum and the first lumbar vertebra (at least
1170-629: Is a junior synonym of Australopithecus . In the spirit of tightening splitting criteria for hominin taxa, in 1954, Robinson suggested demoting " P. crassidens " to subspecies level as " P. r. crassidens ", and also moved the Indonesian Meganthropus into the genus as " P. palaeojavanicus ". Meganthropus has since been variously reclassified as a synonym of the Asian Homo erectus , " Pithecanthropus dubius ", Pongo ( orangutans ), and so on, and in 2019 it
1260-547: Is consistent with a humanlike precision grip which would have made possible the production or usage of tools requiring greater motor functions than non-human primate tools . The femur, as in P. boisei and H. habilis , is flattened anteroposteriorly (on the front and back side). This may indicate a walking gait more similar to early hominins than to modern humans (less efficient gait). Four femora assigned to P. robustus —SK 19, SK 82, SK 97, and SK 3121—exhibit an apparently high anisotropic trabecular bone (at
1350-500: Is debated if P. aethiopicus should be subsumed under P. boisei , and 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 . Like other Paranthropus , P. aethiopicus had a tall face, thick palate , and especially enlarged cheek teeth . However, likely due to its archaicness, it also diverges from other Paranthropus , with some aspects resembling
1440-420: 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
1530-452: Is due to the high manganese content of the material it was embedded in. This fossilized cranium's face projects far outward from the forehead, has wide flared zygomatic arches , and has a large sagittal crest. The molar and premolar roots in the jaw are indicative of this early human having massive cheek teeth; an adaptation for heavy chewing. It is the only known adult skull of the species. While its relationship to other fossil hominin taxa
1620-624: Is found in the context of closed, wet environments, P. aethiopicus seems to have inhabited bushland to open woodland habitats around edaphic (water-logged) grasslands. Around 2.5 million years ago, at the Pliocene / Pleistocene border, the Omo–Turkana Basin featured a mix of forests, woodlands, grasslands, and bushlands, though grasslands appear to have been expanding through the Early Pleistocene . Homo seems to have entered
1710-406: Is generally considered to have been ancestral to P. boisei which also inhabited East Africa, making it a chronospecies . Because of this relationship, it is debatable if P. aethiopicus should be subsumed under P. boisei or if the differences stemming from archaicness should justify species distinction. The terms P. boisei sensu lato ("in the broad sense") and P. boisei sensu stricto ("in
1800-435: Is heavily built, and the palate and base of the skull are about the same size as the P. boisei holotype OH 5 . The brain volume of KNM WT 17000 was estimated to have been 410 cc (25 cu in), which is smaller than that of other Paranthropus . The combination of a tall face, thick palate, and small braincase caused a highly defined sagittal crest on the midline of the skull. The only complete tooth crown of
1890-746: Is known, brain volume cannot be accurately measured for this specimen. In 2001, Polish anthropologist Katarzyna Kaszycka said that Broom quite often artificially inflated brain size in early hominins, and the true value was probably much lower. In 1972, American physical anthropologist Ralph Holloway measured the skullcap SK 1585, which is missing part of the frontal bone , and reported a volume of about 530 cc. He also noted that, compared to other australopithecines, Paranthropus seems to have had an expanded cerebellum like Homo , echoing what Tobias said while studying P. boisei skulls in 1967. In 2000, American neuroanthropologist Dean Falk and colleagues filled in frontal bone anatomy of SK 1585 using
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#17327655142731980-473: Is still debated. It was long assumed that if Paranthropus is a valid genus then P. robustus was the ancestor of P. boisei , but in 1985, anthropologists Alan Walker and Richard Leakey found that the 2.5-million-year-old East African skull KNM WT 17000 —which they assigned to a new species A. aethiopicus|A. aethiopicus —was ancestral to A. boisei (they considered Paranthropus synonymous with Australopithecus ), thus establishing
2070-498: 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. P. aethiopicus is only confidently identified from the skull KNM WT 17000 and a few jaws and isolated teeth, and
2160-433: Is unclear if frequent squatting could be a valid alternative interpretation. The textural complexity of the kneecap SKX 1084, which reflects cartilage thickness and thus usage of the knee joint and bipedality, is midway between modern humans and chimps. The big toe bone of P. robustus is not dextrous, which indicates a humanlike foot posture and range of motion, but the more distal ankle joint would have inhibited
2250-462: The Late Pliocene to Early Pleistocene of East Africa about 2.7–2.3 million years ago. However, it is much debated whether or not Paranthropus is an invalid grouping and is synonymous with Australopithecus , so the species is also often classified as Australopithecus aethiopicus . Whatever the case, it is considered to have been the ancestor of the much more robust P. boisei . It
2340-679: The Mid-Pleistocene Transition characterised by the continual prolonging of dry cycles and subsequent retreat of such habitat. The first remains, a partial skull including a part of the jawbone ( TM 1517 ), were discovered in June 1938 at the Kromdraai cave site , South Africa, by local schoolboy Gert Terblanche. He gave the remains to South African conservationist Charles Sydney Barlow, who then relayed them to South African palaeontologist Robert Broom . Broom began investigating
2430-543: The P. boisei skull KNM-ER 406 was demonstrated to have been contemporaneous with the H. ergaster/H. erectus skull KNM ER 3733 (which is considered a human ancestor). This 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
2520-407: The P. boisei skulls KNM-ER 406 and 729, pointed out that bite force is a measure of not only the total pressure exerted but also the surface area of the tooth over which the pressure is being exerted, and Paranthropus teeth are 4–5 times the size of modern human teeth. Because the chewing muscles are arranged the same way, Walker postulated that the heavy build was instead an adaptation to chew
2610-514: The P. boisei specimens KNM-ER 407, OH 5 , and KNM-ER 732, and recalculated the brain volume to about 476 cc. They stated overall brain anatomy of P. robustus was more like that of non-human apes. In 2020, the nearly complete skull DNH 155 was discovered and was measured to have had a brain volume of 450 cc. In 1983, while studying SK 1585 ( P. robustus ) and KNM-ER 407 ( P. boisei , which he referred to as robustus ), French anthropologist Roger Saban stated that
2700-421: The Pliocene from which they and modern humans descended, and consistent with several hominin taxa existing alongside human ancestors. The Kromdraai taxon, classified as Paranthropus robustus , was later discovered at the nearby Swartkrans Cave in 1948. P. robustus was only definitively identified at Kromdraai and Swartkrans until around the turn of the century when the species was reported elsewhere in
2790-586: The Taung child . In 1936, Broom had described " Plesianthropus transvaalensis " (now synonymised with A. africanus ) from the Sterkfontein Caves only 2 km (1.2 mi) west from Kromdraai. All these species dated to the Pleistocene and were found in the same general vicinity (now called the " Cradle of Humankind "). Broom considered them evidence of a greater diversity of hominins in
KNM WT 17000 - Misplaced Pages Continue
2880-483: The boisei lineage as beginning long before robustus had existed. In 1989, palaeoartist Walter Ferguson recommended KNM WT 17000 be classified into a different species, walkeri , because the holotype of aethiopicus comprised only the jawbone and KNM WT 17000 preserves no jaw elements. Ferguson's classification is almost universally ignored, and is considered to be synonymous with P. aethiopicus . Several more lower and upper jaw specimens have been unearthed in
2970-660: The boisei lineage as beginning long before robustus had existed. The genus Paranthropus (otherwise known as "robust australopithecines", in contrast to the " gracile australopithecines") now also includes the East African P. boisei and P. aethiopicus . It is still debated if this 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 with other australopithecines are difficult to gauge with accuracy. The jaws are
3060-403: The family Hominidae , and non-human great apes into " Pongidae "; in 1950, Broom suggested separating early hominins into the subfamilies Australopithecinae ( Au. africanus and " Pl. transvaalensis "), "Paranthropinae" ( Pa. robustus and " Pa. crassidens "), and "Archanthropinae" (" Au. prometheus "). This scheme was widely criticised for being too liberal in demarcating species. Further,
3150-420: The inner ear of SK 46 and SK 47 are unlike those of the apelike Australopithecus or Homo , suggesting different locomotory and head movement patterns, since inner ear anatomy affects the vestibular system (sense of balance). The posterior semicircular canals of modern humans are thought to aid in stabilisation while running, which could mean P. robustus was not an endurance runner. Upon describing
3240-462: The internal vertebral venous plexuses or internal jugular vein , and was thus related to the reorganisation of the blood vessels supplying the head as an immediate response to bipedalism , which relaxed as bipedalism became more developed. In 1988, Falk and Tobias demonstrated that early hominins (at least A. africanus and P. boisei ) could have both an occipital/marginal and transverse/sigmoid systems concurrently or on opposite halves of
3330-427: The tympanic part of the temporal bone is not as vertically orientated, the base of the skull is weakly flexed, the postglenoid process is completely anterior to (in front of) the tympanic, the tympanic is somewhat tubular, and the articular tubercle is weak. Like P. boisei , the foramen magnum where the skull connects to the spine is heart-shaped. The temporalis muscle was probably not directed as forward as it
3420-409: The 21st century, " P. crassidens " had more or less fallen out of use in favour of P. robustus . American palaeoanthropologist Frederick E. Grine is the primary opponent of synonymisation of the two species. In 1939, Broom hypothesised that P. robustus was closely related to the similarly large-toothed ape Gigantopithecus from Asia (extinct apes were primarily known from Asia at
3510-540: The Cradle of Humankind at Sterkfontein, Gondolin , Cooper's , and Drimolen Caves. The species has not been found outside this small area. In 1948, at the nearby Swartkrans Cave, Broom described " P. crassidens " (distinct from P. robustus ) based on a subadult jaw, SK 6, because Swartkrans and Kromdraai clearly dated to different time intervals based on the diverging animal assemblages in these caves. At this point in time, humans and allies were classified into
3600-617: The Shungura Formation, including a juvenile specimen, L338y-6. In 2002, a 2.7–2.5 Ma maxilla , EP 1500, from Laetoli , Tanzania, was assigned to P. aethiopicus . Also found was the upper portion of a tibia , but it cannot definitively be associated with EP 1500 and thus with P. aethiopicus . The genus Paranthropus (from Ancient Greek παρα para beside or alongside, and άνθρωπος ánthropos man, otherwise known as "robust australopithecines") typically includes P. aethiopicus , P. boisei , and P. robustus . P. aethiopicus
3690-466: The articular surface (where it joins with another vertebra) is kidney -shaped. The T12 is more compressed in height than that of other australopithecines and modern apes. Modern humans who suffer from spinal disc herniation often have vertebrae that are more similar to those of chimpanzees than healthy humans. Early hominin vertebrae are similar to those of a pathological human, including the only other 12th thoracic vertebra known for P. robustus ,
KNM WT 17000 - Misplaced Pages Continue
3780-413: The cave. In 1957, though, Italian biologist Alberto Simonetta moved it to the genus " Pithecanthropus ", and Robinson (without a specific reason why) decided to synonymise it with H. erectus (African H. erectus are sometimes called H. ergaster today). In 1965, South African palaeoanthropologist Phillip V. Tobias questioned whether this classification is completely sound or not. By
3870-403: The cross sectional area of the femoral head for a sample of just humans and a sample with all great apes including humans, and calculated linear regressions for each one. Based on the average of these two regressions, he reported an average weight of 47.1 kg (104 lb) for P. robustus using the specimens SK 82 and SK 97. In 1991, McHenry expanded his sample size, and also estimated
3960-518: The entire species, they said that this degree of sexual dimorphism is greater than what is exhibited in humans and chimpanzees , but less than orangutans and gorillas . Female P. robustus were about the same estimated weight as female H. ergaster/H. erectus in Swartkrans, but they estimated male H. ergaster/H. erectus as much bigger at 55 kg (121 lb). In 2012, American anthropologist Trenton Holliday, using
4050-677: The estimated size of the preserved femur, as 126 cm (4 ft 2 in), 137 cm (4 ft 6 in), and 110 cm (3 ft 7 in), respectively. Based on just these three, he reported an average height of 132 cm (4 ft 4 in) for P. robustus males and 110 cm (3 ft 7 in) for females. In 2001, palaeoanthropologist Randall L. Susman and colleagues, using two recently discovered proximal femoral fragments from Swartkrans, estimated an average of 42 kg (93 lb) for males and 30 kg (66 lb) for females. If these four proximal femur specimens—SK 82, SK 97, SKW 19, and SK 3121—are representative of
4140-456: The finger bones are uncurved and have weaker muscle attachment than non-human apes, though the proximal phalanges are smaller than in humans. The intermediate phalanges are stout and straight like humans, but have stouter bases and better developed flexor impressions. The distal phalanges seem to be essentially humanlike. These could indicate a decreased climbing capacity compared to non-human apes and P. boisei . The P. robustus hand
4230-550: The genus Australopithecus as A. boisei , A. aethiopicus , and A. robustus . British geologist Bernard Wood and American palaeoanthropologist William Kimbel are major proponents of monophyly, and against include Walker. 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 This species, originally named Paraustralopithecus aethiopicus , cannot retain
4320-491: The greater flexion achieved by non-human apes, but the head of radius (the elbow ) seems to have been quite capable of maintaining stability when the forearm was flexed like non-human apes. It is possible this reflects some arboreal activity (movement in the trees) as is controversially postulated in other australopithecines. SKX 3602 exhibits robust radial styloid processes near the hand which indicate strong brachioradialis muscles and extensor retinaculae . Like humans,
4410-483: The group than males, but males may have been more likely to be evicted as indicated by higher male mortality rates and assumed increased risk of predation to solitary individuals. P. robustus contended with sabertooth cats , leopards , and hyenas on the mixed, open-to-closed landscape, and P. robustus bones probably accumulated in caves due to big cat predation. It is typically found in what were mixed open and wooded environments, and may have gone extinct in
4500-426: The hip joint) structure, which could indicate reduced mobility of the hip joint compared to non-human apes, and the ability to produce forces consistent with humanlike bipedalism. The femoral head StW 311, which either belongs to P. robustus or early Homo , seems to have habitually been placed in highly flexed positions based on the wearing patterns, which would be consistent with frequent climbing activity. It
4590-404: The humerus-to-femur ratio of P. robustus by using the presumed female humerus of STS 7 and comparing it with the presumed male femur of STS 14. He also had to estimate the length of the humerus using the femur assuming a similar degree of sexual dimorphism between P. robustus and humans. Comparing the ratio to humans, he concluded that P. robustus was a heavily built species with
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#17327655142734680-464: The juvenile SK 853. Conversely, SK 3981 is more similar to those of healthy humans, which could be explained as: SK 3981 is abnormal, the vertebrae took on a more humanlike condition with maturity, or one of these specimens is assigned to the wrong species. The shape of the lumbar vertebrae is much more similar to that of Turkana Boy ( H. ergaster / H. erectus ) and humans than other australopithecines. The pedicles (which jut out diagonally from
4770-442: The left side: the third premolar measuring 10.7 mm × 13.8 mm (0.42 in × 0.54 in), the fourth premolar measuring 12 mm × 15 mm (0.47 in × 0.59 in), the first molar measuring 15.7 mm × 14.3 mm (0.62 in × 0.56 in), and the second molar measuring 17 mm × 16.7 mm (0.67 in × 0.66 in). The fourth premolar and first molar are
4860-416: The living size of Swartkrans specimens by scaling down the dimensions of an average modern human to meet a preserved leg or foot element (he considered the arm measurements too variable among hominins to give accurate estimates). At Members 1 and 2, about 35% of the P. robustus leg or foot specimens were the same size as those in a 28 kg (62 lb) human, 22% in a 43 kg (95 lb) human, and
4950-428: The lower jaw to the upper jaw, is tall, which would have increased lever arm (and thereby, torque) of the masseter and medial pterygoid muscles (both important in biting down), further increasing bite force. The well-defined sagittal crest and inflated cheeks are absent in the presumed-female skull DNH-7, so Keyser suggested that male P. robustus may have been more heavily built than females ( P. robustus
5040-431: The lower limbs had a wider range of motion than those of modern humans. The distal (lower) humerus of P. robustus falls within the variation of both modern humans and chimps, as the distal humerus is quite similar between humans and chimpanzees. The radius of P. robustus is comparable in form to Australopithecus species. The wrist joint had the same maneuverability as that of modern humans rather than
5130-559: The main argument for monophyly, but jaw anatomy is strongly influenced by diet and environment, and could have evolved independently in P. robustus and P. boisei . 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 the genus Australopithecus as A. boisei , A. aethiopicus , and A. robustus . In 2020, palaeoanthropologist Jesse M. Martin and colleagues' phylogenetic analyses reported
5220-413: The modern human toe-off gait cycle . P. robustus and H. habilis may have achieved about the same grade of bipedality. Broom had noted that the ankle bone and humerus of the holotype TM 1517 were about the same dimensions as that of a modern San woman, and so assumed humanlike proportions in P. robustus . In 1972, Robinson estimated Paranthropus as having been massive. He calculated
5310-594: The monophyly of Paranthropus , but also that P. robustus had branched off before P. aethiopicus (that P. aethiopicus was ancestral to only P. boisei ). The exact classification of Australopithecus species with each other is quite contentious. A. africanus P. aethiopicus P. boisei P. robustus A. africanus P. robustus P. aethiopicus P. boisei A. africanus Homo Kenyanthropus P. robustus P. aethiopicus P. boisei In 2023, fragmentary genetic material belonging to this species
5400-486: The much earlier A. afarensis . P. aethiopicus is known primarily by the skull KNM WT 17000 from West Lake Turkana , Kenya, as well as some jawbones from Koobi Fora; the Shungura Formation , Ethiopia; and Laetoli , Tanzania. These locations featured bushland to open woodland landscapes with edaphic (water-logged) grasslands. In 1968, French palaeontologist Camille Arambourg and Breton anthropologist Yves Coppens described " Paraustralopithecus aethiopicus " based on
5490-407: The nose appears to sit at the bottom of a concavity (a dished face). This displaced the eye sockets forward somewhat, causing a weak brow ridge and receding forehead. The inflated cheeks also would have pushed the masseter muscle (important in biting down) forward and pushed the tooth rows back, which would have created a higher bite force on the premolars. The ramus of the jawbone, which connects
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#17327655142735580-436: The parietal branch of the middle meningeal artery originated from the posterior branch in P. robustus and P. boisei 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, at least for P. boisei , the parietal branch could originate from either the anterior or posterior branches, sometimes both in
5670-593: The ramus would not have been particularly deep (it would have been weaker). This may have produced a less effective bite compared to P. boisei . KNM-WT 16005 is quite similar to the Peninj Mandible assigned to P. boisei , exhibiting postcanine megadontia with relatively small incisors and canines (based on the tooth roots ) and large cheek teeth . Nonetheless, the incisors were likely much broader in KNM-WT 16005. KNM-WT 16005 preserved four cheek teeth on
5760-553: The region 2.5–2.4 million years ago. Paranthropus robustus Paranthropus robustus is a species of robust australopithecine from the Early and possibly Middle Pleistocene of the Cradle of Humankind , South Africa , about 2.27 to 0.87 (or, more conservatively, 2 to 1) million years ago. It has been identified in Kromdraai , Swartkrans , Sterkfontein , Gondolin , Cooper's , and Drimolen Caves. Discovered in 1938, it
5850-443: The remaining 43% bigger than the former but less than a 54 kg (119 lb) human except for KNM‐ER 1464 (an ankle bone ). At Member 3, all individuals were consistent with a 45 kg (99 lb) human. Smaller adults thus seem to have been more common. McHenry also estimated the living height of three P. robustus specimens (male SK 82, male SK 97, and female or subadult SK 3155), by scaling down an average human to meet
5940-560: The remains were not firmly dated, and it was debated if there were indeed multiple hominin lineages or if there was only a single one leading to humans. Most prominently, Broom and South African palaeontologist John Talbot Robinson continued arguing for the validity of Paranthropus . Anthropologists Sherwood Washburn and Bruce D. Patterson were the first to recommend synonymising Paranthropus with Australopithecus in 1951, wanting to limit hominin genera to only that and Homo , and it has since been debated whether or not Paranthropus
6030-507: The robust Kromdraai remains into a new genus , as Paranthropus robustus . " Paranthropus " derives from the Ancient Greek παρα para , beside or alongside; and άνθρωπος ánthropos , man. At this point in time, Australian anthropologist Raymond Dart had made the very first claim (quite controversially at the time) of an early ape -like human ancestor in 1924 from South Africa, Australopithecus africanus , based on
6120-452: The same equation as McHenry on three specimens, reported an average of 37 kg (82 lb) with a range of 30–43 kg (66–95 lb). In 2015, biological anthropologist Mark Grabowski and colleagues, using nine specimens, estimated an average of 32.3 kg (71 lb) for males and 24 kg (53 lb) for females. In 1954, Robinson suggested that the heavily built skull of P. robustus and resultantly exorbitant bite force
6210-551: The site, and, a few weeks later, recovered a right distal humerus (the lower part of the upper arm bone), a proximal right ulna (upper part of a lower arm bone) and a distal phalanx bone of the big toe, all of which he assigned to TM 1517. He also identified a distal toe phalanx which he believed belonged to a baboon , but has since been associated with TM 1517. Broom noted the Kromdraai remains were especially robust compared to other hominins . In August 1938, Broom classified
6300-409: The skull. Few vertebrae are assigned to P. robustus . The only thoracolumbar series ( thoracic and lumbar series) preserved belongs to the juvenile SKW 14002, and either represents the 1st to the 4th lumbar vertebrae, or the 2nd to the 5th. SK 3981 preserves a 12th thoracic vertebra (the last in the series), and a lower lumbar vertebra. The 12th thoracic vertebra is relatively elongated, and
6390-415: The species epithet aethiopicus if moved to genus Australopithecus because Australopithecus aethiopicus is already a junior synonym of Australopithecus afarensis . Such a classification would have to use the name Australopithecus walkeri for this species. The change of species epithet would also happen in a taxonomy that classifies all hominins as Homo . Typical of Paranthropus , KNM WT 17000
6480-421: The species, Broom estimated the fragmentary braincase of TM 1517 as 600 cc, and he, along with South African anthropologist Gerrit Willem Hendrik Schepers, revised this to 575–680 cc in 1946. For comparison, the brain volume of contemporary Homo varied from 500 to 900 cc. A year later, British primatologist Wilfrid Le Gros Clark commented that, since only a part of the temporal bone on one side
6570-447: The specimen SK 1585 is estimated to have been 476 cc, and of DNH 155 about 450 cc (for comparison, the brain volume of contemporary Homo varied from 500 to 900 cc). P. robustus limb anatomy is similar to that of other australopithecines, which may indicate a less efficient walking ability than modern humans, and perhaps some degree of arboreality (movement in the trees). P. robustus seems to have consumed
6660-420: The specimen is the right third premolar , whose dimensions are well above the range of variation for P. robustus and on the upper end for P. boisei . Unlike other Paranthropus , KNM WT 17000 did not have a flat face, and the jaw jutted out ( prognathism ). In regard to the temporal bone , KNM WT 17000 differs from other Paranthropus in that the squamous part of temporal bone is extensively pneumaticised ,
6750-513: The specimens' archaicness or represented the normal range of variation for the species. If the former, they recommended classifying them and similar specimens into a different species, aethiopicus (and recommended that Paraustralopithecus be invalid). The discovery of these archaic specimens overturned previous postulations that P. robustus was the ancestor of the much more robust P. boisei (a hypothesis notably argued by palaeoanthropologist Yoel Rak [ de ] in 1985) by establishing
6840-421: The strict sense") can be used to respectively include and exclude P. aethiopicus from P. boisei when discussing the lineage as a whole. It is also 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
6930-454: The time) believing Gigantopithecus to have been a hominin. Primarily influenced by the mid-century opinions of Jewish German anthropologist Franz Weidenreich and German-Dutch palaeontologist Ralph von Koenigswald that Gigantopithecus was, respectively, the direct ancestor of the Asian H. erectus or closely related, much debate followed over whether Gigantopithecus was a hominin or
7020-419: The tips of the cusps, whereas in humans it thickens at the base of the cusps. P. robustus has a tall face with slight prognathism (the jaw jutted out somewhat). The skulls of males have a well-defined sagittal crest on the midline of the skullcap and inflated cheek bones, which likely supported massive temporal muscles important in biting. The cheeks project so far from the face that, when in top-view,
7110-449: The vertebra) of the lower lumbar vertebra are much more robust than in other australopithecines and are within the range of humans, and the transverse processes (which jut out to the sides of the vertebra) indicate powerful iliolumbar ligaments . These could have bearing on the amount of time spent upright compared to other australopithecines. The pelvis is similar to the pelvises of A. africanus and A. afarensis , but it has
7200-513: The vertebral arch), preserved in DNH 43, are similar to those of other australopithecines. The pelvis seems to indicate a more-or-less humanlike hip joint consistent with bipedalism, though differences in overall pelvic anatomy may indicate P. robustus used different muscles to generate force and perhaps had a different mechanism to direct force up the spine. This is similar to the condition seen in A. africanus . This could potentially indicate
7290-434: Was sexually dimorphic ). The Drimolen material, being more basal, is comparatively more gracile and consequently probably had a smaller bite force than the younger Swartkrans and Kromdraii P. robustus . The brows of the former also are rounded off rather than squared, and the sagittal crest of the presumed-male DNH 155 is more posteriorly (towards the back of the head) positioned. The posterior semicircular canals in
7380-480: Was again argued to be a valid genus. In 1949, also in Swartkrans Cave, Broom and Robinson found a mandible which they preliminary described as "intermediate between one of the ape-men and true man," classifying it as a new genus and species " Telanthropus capensis ". Most immediate reactions favoured synonymising " T. capensis " with " P. crassidens ", whose remains were already abundantly found in
7470-621: Was among the first early hominins described, and became the type species for the genus Paranthropus . However, it has been argued by some that Paranthropus is an invalid grouping and synonymous with Australopithecus , so the species is also often classified as Australopithecus robustus . Robust australopithecines—as opposed to gracile australopithecines—are characterised by heavily built skulls capable of producing high stresses and bite forces , as well as inflated cheek teeth ( molars and premolars ). Males had more heavily built skulls than females. P. robustus may have had
7560-926: Was an omnivore . They found that the microwear patterns in P. robustus suggest hard food was infrequently consumed, and therefore the heavy build of the skull was only relevant when eating less desirable fallback foods. Such a strategy 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 chimpanzees (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
7650-428: Was in P. boisei , meaning the P. aethiopicus jaw likely processed food with the incisors before using the cheek teeth. The incisors of P. boisei are thought to have not been involved in processing food. The long distance between the first molar and the jaw hinge would suggest KNM WT 17000 had an exceptionally long ramus of the mandible (connecting the lower jaw to the skull), though the hinge's location indicates
7740-570: Was indicative of a specialist diet adapted for frequently cracking hard foods such as nuts. Because of this, the predominant model of Paranthropus extinction for the latter half of the 20th century was that they were unable to adapt to the volatile climate of the Pleistocene, unlike the much more adaptable Homo . Subsequent researchers reinforced this model studying the musculature of the face, dental wearing patterns, and primate ecology. In 1981, English anthropologist Alan Walker, while studying
7830-605: 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 . The matter
7920-450: Was not immediately clear at the time of its discovery, further studies have suggested it is a possible ancestor of two species: Paranthropus boisei , of east Africa, and Paranthropus robustus , of South Africa . This prehistoric hominin -related article is a stub . You can help Misplaced Pages by expanding it . Paranthropus aethiopicus Paranthropus aethiopicus is an extinct species of robust australopithecine from
8010-461: Was reported from 2 million year-old teeth, being the oldest genetic evidence to be retrieved from a human. Typical of Paranthropus , P. robustus exhibits post-canine megadontia with enormous cheek teeth but human-sized incisors and canines . The premolars are shaped like molars . The enamel thickness on the cheek teeth is relatively on par with that of modern humans, though australopithecine cheek tooth enamel thickens especially at
8100-402: Was soon challenged in 1974 by American palaeontologist Stephen Jay Gould and English palaeoanthropologist David Pilbeam , who guessed from the available skeletal elements a weight of about 40.5 kg (89 lb). Similarly, in 1988, American anthropologist Henry McHenry reported much lighter weights as well as notable sexual dimorphism for Paranthropus . McHenry plotted body size vs.
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