Pages in category "Prehistoric Kenya"
The following 19 pages are in this category, out of 19 total. This list may not reflect recent changes (learn more).
The following 19 pages are in this category, out of 19 total. This list may not reflect recent changes (learn more).
1. Australopithecus afarensis – Australopithecus afarensis is an extinct hominin that lived between 3.9 and 2.9 million years ago. A. afarensis was slenderly built, like the younger Australopithecus africanus, a. afarensis is thought to be more closely related to the genus Homo, whether as a direct ancestor or a close relative of an unknown ancestor, than any other known primate from the same time. Some researchers include A. afarensis in the genus Praeanthropus, the most famous fossil is the partial skeleton named Lucy found by Donald Johanson and colleagues, who, in celebration of their find, repeatedly played the Beatles song Lucy in the Sky with Diamonds. Australopithecus afarensis fossils have only been discovered within Eastern Africa, despite Laetoli being the type locality for A. Other localities bearing A. afarensis remains include Omo, Maka, Fejej, and Belohdelie in Ethiopia, compared to the modern and extinct great apes, A. afarensis has reduced canines and molars, although they are still relatively larger than in modern humans. A. afarensis also has a small brain size and a prognathic face. Considerable debate surrounds the locomotor behaviour of A. afarensis, some studies suggest that A. afarensis was almost exclusively bipedal, while others propose that the creatures were partly arboreal. The anatomy of the hands, feet, and shoulder joints in many ways favour the latter interpretation, in particular, the morphology of the scapula appears to be ape-like and very different from modern humans. The curvature of the finger and toe bones approaches that of modern-day apes, alternatively, the loss of an abductable great toe and therefore the ability to grasp with the foot suggests A. afarensis was no longer adapted to climbing. A number of traits in the A. afarensis skeleton strongly reflect bipedalism, in overall anatomy, the pelvis is far more human-like than ape-like. The iliac blades are short and wide, the sacrum is wide and positioned directly behind the hip joint, importantly, the femur also angles in toward the knee from the hip. This trait would have allowed the foot to have closer to the midline of the body. The feet also feature adducted big toes, making it difficult if not impossible to grasp branches with the hindlimbs. The loss of a grasping hindlimb also increases the risk of an infant being dropped or falling, without the second set of grasping limbs, the infant cannot maintain as strong a grip, and likely had to be held with help from the mother. The problem of holding the infant would be multiplied if the mother also had to climb trees, bones of the foot also indicate bipedality. The upright gait would have much more efficient than the bent knee and hip walking. Yet, this can be questioned, as finds of Australopithecus foot bones indicate the Laetoli footprints may not have made by Australopithecus. Many scientists also doubt the suggestion of bipedalism, and argue that even if Australopithecus really did walk on two legs, it did not walk in the way as humans
2. Australopithecus anamensis – Australopithecus anamensis is a stem-human species that lived approximately four million years ago. Nearly one hundred specimens are known from Kenya and Ethiopia. It is accepted that A. anamensis is ancestral to A. afarensis, fossil evidence determines that the Australopithecus anamensis is the earliest hominin species in the Turkana Basin. Due to an inability to retrieve a collection of fossils researchers are not able to make enough observations to differentiate a lot of the early hominids. The specimen was assigned at the time to Australopithecus and dated about four million years old. One method used to determine the age of the Kanapoi fossils was based on faunal correlation data, based on the limited postcranial evidence available, A. anamensis appears to have been habitually bipedal, although it retained some primitive features of its upper limbs. Leakey determined that this species was independent of many others and it does not represent an intermediate species of any type. Although the excavation team did not find hips, feet or legs, tree climbing was one behavior retained by early hominins until the appearance of the first Homo species about 2.5 million years ago. A. anamensis shares many traits with Australopithecus afarensis and may well be its direct predecessor. Fossil records for A. anamensis have been dated to between 4.2 and 3.9 million years ago, with recent findings from stratigraphic sequences dating to about 4. 1–4. 2 million years ago. Specimens have been found two layers of volcanic ash, dated to 4.17 and 4.12 million years. The fossils include upper and lower jaws, cranial fragments, in addition to this, the aforementioned fragment of humerus found thirty years ago at the same site at Kanapoi has now been assigned to this species. In 2006, a new A. anamensis find was officially announced, specifically, one site known as Asa Issie provided 30 A. anamensis fossils. These new fossils, sampled from a context, include the largest hominid canine tooth yet recovered. Ardipithecus was a primitive hominid, considered the next known step below Australopithecus on the evolutionary tree. Australopithecus anamensis was found in Kenya, specifically at Allia Bay, through analysis of stable isotope data, it is believed that their environment had more closed woodland canopies surrounding Lake Turkana than are present today. The greatest density of woodlands at Allia Bay was along the ancestral Omo River, there was believed to be more open savanna in the basin margins or uplands. Similarly at Allia Bay, it is suggested that the environment was much wetter, while it is not definitive, it also could have been possible that nut or seed-bearing trees could have been present at Allia Bay, however more research is needed
3. Homo erectus – Homo erectus is an extinct species of hominid that lived throughout most of the Pleistocene geological epoch. Its earliest fossil evidence dates to 1.9 million years ago and extends to 70,000 years ago, or, possibly, as recently as 35,000 years ago. It is generally thought that H. erectus originated in Africa and spread from there, migrating throughout Eurasia as far as Georgia, India, Sri Lanka, China, a new debate appeared in 2013, with the documentation of the Dmanisi skulls.58 million years ago. From there it migrated, in part, by 2, the fossil record shows that its development from about 1.8 mya to one mya was widely distributed, in Africa, the Transcaucasus, Indonesia, and in Vietnam, China, and India. The second hypothesis is that H. erectus evolved in Eurasia and they occupied the Dmanisi site from 1.85 million to 1.77 million years ago, which was about the same time or slightly before their earliest evidence in Africa. There are several proposed explanations of the dispersal of H. erectus georgicus—including whether or not Africa is the source), the Dutch anatomist Eugène Dubois was fascinated by Darwins theory of evolution especially as it applied to humankind. In 1886, he set out for Asia—which then was the region accepted as the cradle of evolution despite Darwins theory of African origin. In 1891, his team discovered a human fossil on the island of Java, the Java fossil from Indonesia aroused much public interest. It was dubbed by the press as Java Man, but few scientists accepted Dubois argument that his fossil was the transitional form—the so-called missing link—between apes. Java Man is now classified as Homo erectus, most of the spectacular discoveries of H. erectus next took place at the Zhoukoudian Project, now known as the Peking Man Site, in Zhoukoudian, China. This site was first discovered by Johan Gunnar Andersson in 1921 and was first excavated in 1921, canadian anatomist Davidson Blacks initial description of a lower molar as belonging to a previously unknown species prompted widely publicized interest. Extensive excavations followed, which altogether uncovered 200 human fossils from more than 40 individuals including five nearly complete skullcaps, german anatomist Franz Weidenreich provided much of the detailed description of this material in several monographs published in the journal Palaeontologica Sinica. Throughout much of the 20th century, anthropologists debated the role of H. erectus in human evolution, early in the century, due in part to the discoveries at Java and Zhoukoudian, it was widely accepted that modern humans first evolved in Asia. From the 1950s forward, numerous finds in East Africa confirmed the hypothesis of an African genesis and it is now generally accepted that H. erectus descended from either, 1) the earliest hominin genera, or 2) the earliest Homo-species. East Africa provided sympatric coexistence for H. erectus and H, in the 1950s, archaeologists John T. Robinson and Robert Broom named Telanthropus capensis, Robinson had discovered a jaw fragment in 1949 in Swartkrans, South Africa. Later, Simonetta proposed to re-designate it to Homo erectus, in 1961, Yves Coppens discovered a skull of Tchadanthropus uxoris, then the earliest fossil human discovered in north Africa. It was reported that the fossil had been so eroded by sand that it mimicked the appearance of an australopith. Although at first considered to be a specimen of H. habilis, T. uxoris is no longer considered a valid taxon, and has been subsumed into H. erectus
4. Homo habilis – Homo habilis is a species of the tribe Hominini, during the Gelasian and early Calabrian stages of the Pleistocene period, which lived between roughly 2.1 and 1.5 million years ago. LD 350-1 is a fossil jawbone fragment discovered in 2013 which has dated to 2.8 million years ago. There has been debate regarding its placement in the genus Homo rather than the genus Australopithecus. The small size and rather primitive attributes have led experts to propose excluding H. habilis from the genus Homo. These were later classified as milk teeth, and therefore considered difficult to link to taxa unlike permanent teeth, however, in 1959, Mary Leakey recovered the cranium of a young adult which had a small brain, large face, tiny canines and massive chewing teeth. H. habilis was short and had long arms compared to modern humans, however. H. habilis had a capacity slightly less than half of the size of modern humans. Despite the ape-like morphology of the bodies, H. habilis remains are accompanied by primitive stone tools. Homo habilis has often thought to be the ancestor of the more gracile and sophisticated Homo ergaster. New findings in 2007 seemed to confirm the view that H. habilis and H. erectus coexisted, an alternative explanation would be that any ancestral relationship from H. habilis to H. erectus would have to have been cladogenetic rather than anagenetic. Its brain size has been shown to range from 550 cm3 to 687 cm3, a virtual reconstruction published in 2015 estimated the endocranial volume at between 729 and 824 ml, larger than any previously published value. H. habilis brain capacity of around 640 cm³ was on average 50% larger than australopithecines and these hominins were smaller than modern humans, on average standing no more than 1.3 m tall. A fragment of fossilized jawbone, dated to around 2.8 million years ago, was discovered in the Ledi-Geraru research area in Afar Regional State in 2013. The fossil is considered the earliest evidence of the Homo genus known to date, the individual in question lived just after a major climate shift in the region, when forests and waterways were rapidly replaced by arid savannah. One set of remains, discovered by Donald Johanson and Tim White in Olduvai Gorge in 1986, included the important upper and lower limbs, specifically the humerus. Their finding stimulated some debate at the time, locomotor affinities of OH62 have been assessed primarily on the basis of its forelimb to hind limb proportions, which are known to be associated with locomotor behavior among living primates. Initial analyses concentrated on comparisons to the Australopithecus afarensis A. L. 288-1, in most dimensions—measured or estimated—the OH62 upper limb remains equaled or exceeded those of A. L. 288-1, while its lower limb remains appeared to be smaller. In this sense, it was more ‘‘primitive than A. L. 288-1, KNM ER1813 is a relatively complete cranium which dates to 1.9 million years old, discovered at Koobi Fora, Kenya by Kamoya Kimeu in 1973
5. Homo rudolfensis – The scientific name Pithecanthropus rudolfensis was proposed in 1978 by V. P. Alekseyev who later changed it to Homo rudolfensis for the specimen Skull 1470. On 8 August 2012, a team led by Meave Leakey announced the discovery of a face, the fossil KNM-ER1470 was the center of much debate concerning its species. The skull was at first incorrectly dated at nearly three years old, predating the Homo habilis species. Since then, the estimate has been corrected to 1 and it is not certain whether H. rudolfensis, H. habilis or some, as of yet undiscovered, third species was ancestral to the later Homo line. In March 2007, a team led by Timothy Bromage, an anthropologist at New York University, reconstructed the skull of KNM-ER1470. Bromage said his teams reconstruction included biological knowledge not known at the time of the skulls discovery, a newer publication by Bromage has since increased the cranial capacity estimate back up, from 526 cm³ to 700 cm³. When compared to other older H. habilis fossils like OH24, KNM-ER1470 displays less prognathism and a rounder brain case. After much debate, but no settlement, fossil KNM ER1813 was found in 1973 by Kamoya Kimeu. When compared to ER1813, ER1470 manifests a larger braincase ranging from 750-800ml, even if sexual dimorphism were considered, the size difference in the mandible and teeth would be too great compared to KNM-ER1813. Fossil KNM-ER1470, a male H. rudolfensis, has massive teeth in comparison to the female H. habilis fossil KNM-ER1813 and portrays a much larger brain case than KNM-ER1813. When KNM-ER1813 and KNM-ER1470 are compared to OH24 and these similarities include smaller orbits, the projection of the mid-face below the nose and a smaller skull size over all. The face was of a juvenile, but had features in common with KNM-ER1470, suggesting that the latter skulls uniqueness is due to being a separate species, rather than a large male H. habilis. Team member Fred Spoor described the face as incredibly flat, with a line from the eye socket to the incisor tooth. The jawbones, which appeared to match KNM-ER1470 and KNM-ER62000, were also shorter, the fossils were dated to about two million years ago, being contemporaneous with H. habilis. According to Leakey et al. the new fossils confirm the presence of two species of early Homo, in addition to Homo erectus, in the early Pleistocene of eastern Africa. Lee Rogers Berger, however, called the argument weak, and proposed the finds be compared to other possibilities, such as Australopithecus africanus and Australopithecus sediba. Tim D. Leakey replied, I would challenge Tim to find any primate in which you would see the same degrees of variation as those that we are seeing between our new fossils and KNM-ER1802. KNM-ER1802 is a fossil that is thought to be of a Homo rudolfensis
6. Kenyanthropus – Kenyanthropus platyops is a 3.5 to 3. 2-million-year-old hominin fossil discovered in Lake Turkana, Kenya in 1999 by Justus Erus, who was part of Meave Leakeys team. The species name “platyops” is derived from two Greek words, platus, which means flat, and opsis, which means face and this indicated that species were much more diverse in the distant past than previously thought. Even with the findings of a skull, their diet is still unknown at this time. Also, no evidence of culture or anything that would lead to its behavioral adaptations or lifestyle has been discovered at this time. Several aspects of the environment in which it may have lived have been proposed and it is believed that they lived in a “mosaic” environment, which had both grassland and some forested areas. In 1999, Meave Leakey led an expedition in Kenya to dig for fossils, the first expedition was in 1998 in which the paratype, KNM-WT38350 was discovered. They began to dig at a site that had yielded many other prominent hominin fossil specimens, Lake Turkana, a member of the team, Justus Erus, discovered a skull in the Nachukui Formation at Lomekwi, an area of specific geology right next to the lake. KNM-WT40000 and the bones were collected from a dark mudstone. The mudstone was located in between the Lokochot Tuff and the Tulu Bor Tuff in the Kataboi Member, beneath the Lokochot Tuff were the Moiti Tuff and the Topernawi Tuff. The KNM-WT40000 specimen was dated at 3.5 million years, directly beneath the bed was the KNM-WT38341 specimen, which was dated at 3.53 million years. Other specimens from various localities that were found above the b-Tulu Bor Tuff were dated at around 3.3 million years, the location of the mudstone was near a shallow lake, suggesting that the hominins lived near rivers or lakes. KNM-WT40000 is the holotype, the specimen of which the description, the fossils of Kenyanthropus platyops indicate that hominins were more taxonomically diverse during the middle Pliocene. The discovery of this fossil also dated non forward-projecting jaws further back than previous discoveries, the facial structure of the Kenyanthropus and its derived features were very different of that of the Paranthropus, including almost every cranial feature. This gave no reason to assign the new skull in the genus Paranthropus and it is still thought that the differences in cranial structure are too different for even that to be a possibility. The Kenyanthropus also shows many differences to Homo, as well as Ardipithecus, having smaller molars at the date they existed, it is possible that the previous sister taxon of all modern hominins, Preanthropus afarensis, should be replaced by Kenyanthropus. Fragmentary specimens which were having trouble being classified are now being assessed to see if they fit with the Kenyanthropus, the Kenyanthropus platyops was examined by Collard and Wood to have two types of characteristics categorized as craniometric and traditional. Craniometric characters represent size-adjusted linear measurements between standard cranial landmarks, traditional characters represent those most commonly used in systematic studies of apes and early hominids. These characters can be quantitative and qualitative, Kenyanthropus platyops was singled out by the morphology of the maxilla, characterized by a flat and relatively orthognathic subnasal region, an anteriorly placed zygomatic process and small molars
7. KNM ER 992 – KNM ER992 is a 1.5 million years old fossilized lower jaw discovered by Richard Leakey in 1971 at Lake Turkana, Kenya. The mandible was considered by C, groves and V. Mazak to be the holotype specimen for Homo ergaster. List of fossil sites List of hominina fossils Media related to KNM ER992 at Wikimedia Commons Homo ergaster lower jaw cast, archived from the original on July 11,2006
8. KNM ER 1813 – KNM ER1813 is a skull of the species Homo habilis. It was discovered in Koobi Fora, Kenya by Kamoya Kimeu in 1973 and its characteristics include an overall smaller size than other Homo habilis finds, but with a fully adult and typical H. habilis morphology. It is an adult with a cranial capacity of only 510 cc. The designation indicates specimen 1813, collected from the east shore of Lake Rudolf for the Kenya National Museums, List of fossil sites List of hominina fossils Media related to KNM-ER1813 at Wikimedia Commons Archaeology Info Smithsonian Institution