Catalog no. | KNM ER 406 |
---|---|
Species | Paranthropus boisei |
Age | c. 1.7 million years |
Place discovered | Koobi Fora, Kenya |
Date discovered | 1969 |
Discovered by | Richard Leakey and H. Mutua |
KNM ER 406 is an almost complete fossilized skull of the species Paranthropus boisei . [1] It was discovered in Koobi Fora, Kenya by Richard Leakey and H. Mutua in 1969. [2] This species is grouped with the Australopitecine genus, Paranthropus boisei because of the robusticity of the skull and the prominent characteristics. This species was found well preserved with a complete cranium but lacking dentition. He was known for his robust cranial features that showed the signs of adaptation of the ecological niches. The big chewing muscles attached to the sagittal crest are traits of this adaptation. [3]
Following a three-month expedition funded by the National Museums of Kenya, Richard Leakey and H. Mutua spent the summer of 1969 in northern Kenya. This expedition along with the field work three months prior to this project was possible with the financial assistance from the Kenyan Government. During this expedition, there were two specimens that have similar characteristics as seen in the robust KNM-ER 406. The two specimens are Demi-cranium KNM-ER 732 and KNM-ER 407. These two specimens were also robust, but the skulls were considered more gracile. The smaller skulls are evidence that sexual dimorphism was the reason for the size difference. Consistent evidence of Lower Pleistocene hominids supports that there was a variation in size of the Australopithecus in East Rudolf, and not a separate species. [4]
With the occipital only being present the morphology could not be confirmed, but the KNM-ER 406 and the other fossil found a mile North of the site are consistent with fossils found in Olduvai. It has been accepted that they are Australopithecus boisei and it's also been accepted that the A. boisei was not a tool maker. [4]
Another species, called Homo ergaster was discovered and dated the same age as A. Boisei 1.7 million years ago. In 1975, this species was found in northern Kenya, Koobi Fora by Bernard Ngeneo. The same age of 1.7 million years ago means that different species were on the scene in Africa at the same time. Yes, they coexisted. It's known that a species can survive when they inhabit a specific ecological niche. The morphology was different because of the resources they consumed. The Homo ergaster hunted and ate softer foods and more meat. His skull looked more like modern humans. But, A. Boisei’s skull was robust and had large temporals muscles that helped crush nuts and hard plants. It's important to note that these two species coexisted. [5]
Cranial features and brain size
It is an adult male with an estimated cranial capacity of 510 cc and age of 1.7 million years.
Compared to the modern human and the Homo ergaster the A. boisei had a cranial capacity of 510 cc, a much smaller brain then modern humans who have a cranial capacity of 1200-1400 cc. He had striking robusticity, projecting glabella, and a well developed sagittal crest. There are feature differences of the sagittal crest in the KNM-ER 406 and the robust male gorillas and chimpanzees. Roughness appears in the sagittal crest and its located further back by the nuchal crest of gorillas and apes. The KNM-ER 406 sagittal crest is situated near the frontal bone and the highest point of the sagittal crest is located more medially. The development of the robusticity comes from the anterior part of the temporals muscles. As a result of this massiveness size of temporals muscles KNM-ER 406 shows presents of shallow orbits. [6] This species is suggested to be male and his features are the same as Paranthropus boisei and the OH 5. [7] This specimen is perhaps the most impressive skull found.
Homo habilis is an extinct species of archaic human from the Early Pleistocene of East and South Africa about 2.3 million years ago to 1.65 million years ago (mya). Upon species description in 1964, H. habilis was highly contested, with many researchers recommending it be synonymised with Australopithecus africanus, the only other early hominin known at the time, but H. habilis received more recognition as time went on and more relevant discoveries were made. By the 1980s, H. habilis was proposed to have been a human ancestor, directly evolving into Homo erectus, which directly led to modern humans. This viewpoint is now debated. Several specimens with insecure species identification were assigned to H. habilis, leading to arguments for splitting, namely into "H. rudolfensis" and "H. gautengensis" of which only the former has received wide support.
Kenyanthropus is a genus of extinct hominin identified from the Lomekwi site by Lake Turkana, Kenya, dated to 3.3 to 3.2 million years ago during the Middle Pliocene. It contains one species, K. platyops, but may also include the 2 million year old Homo rudolfensis, or K. rudolfensis. Before its naming in 2001, Australopithecus afarensis was widely regarded as the only australopithecine to exist during the Middle Pliocene, but Kenyanthropus evinces a greater diversity than once acknowledged. Kenyanthropus is most recognisable by an unusually flat face and small teeth for such an early hominin, with values on the extremes or beyond the range of variation for australopithecines in regard to these features. Multiple australopithecine species may have coexisted by foraging for different food items, which may be reason why these apes anatomically differ in features related to chewing.
Paranthropus is a genus of extinct hominin which contains two widely accepted species: P. robustus and P. boisei. However, the validity of Paranthropus is contested, and it is sometimes considered to be synonymous with Australopithecus. They are also referred to as the robust australopithecines. They lived between approximately 2.9 and 1.2 million years ago (mya) from the end of the Pliocene to the Middle Pleistocene.
Homo ergaster is an extinct species or subspecies of archaic humans who lived in Africa in the Early Pleistocene. Whether H. ergaster constitutes a species of its own or should be subsumed into H. erectus is an ongoing and unresolved dispute within palaeoanthropology. Proponents of synonymisation typically designate H. ergaster as "African Homo erectus" or "Homo erectus ergaster". The name Homo ergaster roughly translates to "working man", a reference to the more advanced tools used by the species in comparison to those of their ancestors. The fossil range of H. ergaster mainly covers the period of 1.7 to 1.4 million years ago, though a broader time range is possible. Though fossils are known from across East and Southern Africa, most H. ergaster fossils have been found along the shores of Lake Turkana in Kenya. There are later African fossils, some younger than 1 million years ago, that indicate long-term anatomical continuity, though it is unclear if they can be formally regarded as H. ergaster specimens. As a chronospecies, H. ergaster may have persisted to as late as 600,000 years ago, when new lineages of Homo arose in Africa.
Homo rudolfensis is an extinct species of archaic human from the Early Pleistocene of East Africa about 2 million years ago (mya). Because H. rudolfensis coexisted with several other hominins, it is debated what specimens can be confidently assigned to this species beyond the lectotype skull KNM-ER 1470 and other partial skull aspects. No bodily remains are definitively assigned to H. rudolfensis. Consequently, both its generic classification and validity are debated without any wide consensus, with some recommending the species to actually belong to the genus Australopithecus as A. rudolfensis or Kenyanthropus as K. rudolfensis, or that it is synonymous with the contemporaneous and anatomically similar H. habilis.
The Olduvai Gorge or Oldupai Gorge in Tanzania is one of the most important paleoanthropological localities in the world; the many sites exposed by the gorge have proven invaluable in furthering understanding of early human evolution. A steep-sided ravine in the Great Rift Valley that stretches across East Africa, it is about 48 km long, and is located in the eastern Serengeti Plains within the Ngorongoro Conservation Area in the Olbalbal ward located in Ngorongoro District of Arusha Region, about 45 kilometres from Laetoli, another important archaeological locality of early human occupation. The British/Kenyan paleoanthropologist-archeologist team of Mary and Louis Leakey established excavation and research programs at Olduvai Gorge that achieved great advances in human knowledge and are world-renowned. The site is registered as one of the National Historic Sites of Tanzania.
Paleoanthropology or paleo-anthropology is a branch of paleontology and anthropology which seeks to understand the early development of anatomically modern humans, a process known as hominization, through the reconstruction of evolutionary kinship lines within the family Hominidae, working from biological evidence and cultural evidence.
Paranthropus aethiopicus is an extinct species of robust australopithecine from 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 is debated if P. aethiopicus should be subsumed under P. boisei, and the terms P. boisei sensu lato and P. boisei sensu stricto can be used to respectively include and exclude P. aethiopicus from P. boisei.
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptionally strong jaw muscles. The sagittal crest serves primarily for attachment of the temporalis muscle, which is one of the main chewing muscles. Development of the sagittal crest is thought to be connected to the development of this muscle. A sagittal crest usually develops during the juvenile stage of an animal in conjunction with the growth of the temporalis muscle, as a result of convergence and gradual heightening of the temporal lines.
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 million years ago. It has been identified in Kromdraai, Swartkrans, Sterkfontein, Gondolin, Cooper's, and Drimolen Caves. Discovered in 1938, it 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.
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 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.
Koobi Fora refers primarily to a region around Koobi Fora Ridge, located on the eastern shore of Lake Turkana in the territory of the nomadic Gabbra people. According to the National Museums of Kenya, the name comes from the Gabbra language:
In the language of the Gabbra people who live near the site, the term Koobi Fora means a place of the commiphora and the source of myrrh...
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