Fluorine dating piltdown man prognathic

Australopithecine Evolution

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The big-brained, ape-jawed Piltdown Man was hailed as a major . using the then-new technique of fluorine dating—which relies on the fact. Important Points to Remember about Radiocarbon Dating: . , Piltdown Man fraud – fit preconceptions about early human – ape-like face + big brain. . small cranial capacity (roughly cc); relatively large, prognathic ( projecting). Piltdown Man: a fraudulent fossil composed of a human cranium and an ape Radiocarbon dating (also referred to as carbon dating or carbon dating) is a.

Raymond Dart was the first to describe an australopithecine in the literature when he published a description of the now famous Taung Child discovered in South Africa the previous year.

This individual was a juvenile specimen attributed to the species Australopithecus africanus. This nomenclature can largely be attributed to the ape-like features of the cranium and the location of its discovery a Limestone cave in South Africa. However, since this time, the genus has been discovered in the eastern part of Africa as well. The defining features of the australopithecines as a clade can be summarized as follows White All australopithecines possess anatomical characteristics of the pelvis, femur and spinal column that facilitate bipedal locomotion.

Whether or not the australopithecines were fully adapted bipeds is still hotly debated in the literature. There are several important adaptations to bipedal locomotion that can be observed on skeletal material. First, the foramen magnum is shifted forward, underneath the skull. This positioning is indicative of the angle at which the spinal chord enters the skull Tobias, The 's' shape of the spine aids in balancing while walking on two legs Johanson and Edgar, Adaptations more directly related to bipedal locomotion can be observed in the pelvis, the bones of the leg and the foot.

The pelvis of a bipedal hominid is wide, with relatively short ilia that form a basin to support the internal organs. This arrangement facilitates the positioning of the hip muscles laterally with respect to the legs, ehancing balance while walking on two legs Johanson and Edgar, The neck of the femur is lengthened in bipeds, adding leverage to the hip abductors and increasing the efficiency of bipedal locomotion Boyd and Silk, Additionally, the articulation between the femur and the pelvis, and the arrangement of the knee ensure good distribution of weight while walking Johanson and Edgar, The tibia also displays several features which indicate weight transfer from one leg to another: The first bipeds were likely hominids that predated the australopithecines.

Although postcranial evidence of hominids pre-dating the australopithecines is relatively rare, the positioning of the foramen magnum on the cranium of some fossil specimens is suggestive of their status as bipeds Ahern, This is true of both Ardipithecus ramidus ca. Furthermore, while it has been suggested that another pre-australopithecine species Orrorin tugenesis was an adept biped based on its relatively complete postcranial remains Pickford et al.

The past fifteen years have seen several important pre-australopithecine fossils emerge as potential ancestors, but the origin of the australopithecines and bipedalism remains unclear for a more complete assessment of the origins of bipedalism, see Harcourt-Smith and Aiello, ; Stanford, Limb indexes such as the brachial index are useful for reconstructing the locomotor habits of hominids.

Generally, primate species that are leapers have long hindlimbs and thus low intermembral indicessuspensory species e. Pongo have high brachial and intermembral indices and quadrupedal species Pan have intermediate indices Fleagle, As was already discussed, morphological evidence indicates that the australopithecines were bidepal.

The fact that their brachial indices are high suggests that they may still have utilized arboreal habitats, possibly for sleeping, foraging or evading predators; these behaviors have been discussed at length by several authors e.

Sabater Pi et al.

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The degree of sexual dimorphism 3 present in the australopithecines has been hotly debated. For some skeletal samples, there is debate about whether a high degree of sexual dimorphism exists or whether there are two species of hominid present in the sample, one large and one small Johanson and Edey, While it is by no means conclusive due to the uncertainty inherent in estimating body size from fossil specimens, it now appears that the australopithecines exhibited a degree of sexual dimorphism considerably greater than that observed in modern humans and chimpanzees, but less than that observed in gorillas Larsen, Interestingly though, most australopithecines are relatively rare among anthropoids in being highly dimorphic in terms of body size, but not in canine size 7.

The degree of sexual dimorphism is significant because this has implications for social organization and mating systems. Generally, primate species that exhibit high degrees of sexual dimorphism are characterized by intense male-male competition and a polygynous social organization Fleagle, ; Plavcan and van Schaik, Unfortunately, it is difficult to use extant primates as analogies for the australopithecines because no species exhibit the same pattern of canine and body size dimorphism.

However, it has been suggested that social organization was centered around multi-male co-operating kin groups Larsen, As was already mentioned, body size is notoriously difficult to estimate from fragmentary fossil specimens.

Furthermore, some species of australopithecine are known from a very small set of remains, making it even more difficult to estimate body size. However, several species are represented by a relatively good record and estimates of their body size and stature 4 are presented below in Table 1. For comparitive purposes, the sizes of several extant species are included from Ankel-Simons, ; Johanson and Edgar, ; Jones et al.

This table demonstrates a relatively uniform distribution in body size across the australopithecines.

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In terms of body mass, they are relatively comparable to Pan, but are considerably taller, likely as a result of their adaptation to bipedal locomotion. Furthermore, the degree of body size sexual dimorphism can also be observed. Although a general trend in human evolution is an increase in cranial capacity, this trend does not really become marked until the appearance of the genus Homo.

The cranial capacities of the australopithecines 5 are relatively similar see Table 2. It should be pointed out that these cranial volumes be approached with caution and considered only with respect to overall body mass. The cognitive abilities of the australopithecines are largely unknown, but clear evidence indicates that at least some species were manufacturing and using crude stone tools by 2.

It is likely that tools of a more perishable variety composed of organic materials were made and used at an even earlier date, but taphonomic processes do not allow for the preservation of such materials Schick and Toth, There is no indication that the australopithecines possessed any linguistic capabilities.

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The implications of the cognitive abilities of the australopithecines will be addressed in more detail below. It should noted that these estimates are often based on a very small number of specimens. The dentition of the australopithecines is particularly important because the most abundant fossils are isolated teeth, and an examination of the morphology of teeth can be used to determine both phylogenetic relationships, diet and social organization.

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The postcanine dentition is quite large and the enamel is very thick 6 in the australopithecines, especially Paranthropus. Extant primate species with thick enamel tend to feed on hard objects, such as fibrous plant material, nuts and seeds; a similar diet has been proposed for the australopithecines based on their dentition Teaford, Views on what the earliest ancestors of humans may have been eating have changed considerably in the last fifty years, and there is still no consensus on the part of paleoanthropologists.

Early paleoanthropological discourse was centered heavily on the consumption of meat in the early hominid diet see Krantz, ; Lee and DeVore, ; Washburn, A particularly violent image was constructed for the australopithecines, often involving intense conflict see Keyes Roper,cannibalism e.

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Emiliani, and hunting of game e. Brown and Lahren, ; Isaac, ; Krantz, Interestingly, these hypotheses were based on little evidence and were eventually abandoned. One of the major implications of meat-eating was an associated increase in cranial capacity Aiello and Wheeler,but this trend was not observed until the appearance of the genus Homo. While meat-consumption remained an important point of discussion throughout the twentieth century, there was an increase in the focus on the plant component of early hominid diets beginning in the late s and early s e.

Dahlberg, ; Tanner, The shift in focus was co-incident with an increase in the amount of discussion of the role of women in human evolution.

The contemporary literature considers both the consumption of meat and plant foods. The context in which meat was thought to be consumed has changed dramatically.

There has been an increase in the consideration of the scavenging rather than hunting capabilities of early hominids e. The scavenging hypothesis is largely constructed on the interpretations of cut marks on mammalian remains and reconstructions of paleoecological conditions, carnivore guild for example Shipman, However, more recent interpretations of these faunal remains indicates that it is very questionable whether early hominids were actually responsible for the accumulation of these bones Rose and Marshall, There has also been a shift in opinion with respect to the potential hunting abilities of early hominids, with a move towards viewing them as being incapable of competing with larger carnivores due to their limited cognitive abilities, crude toolkit and relatively small size e.

However, given the amplitude of evidence for hunting behavior in Pan that has emerged over the past forty years Stanford,; Takahata et al. Furthermore, an analysis of the physiology of the gastrointestinal tract and scavenging behavior in contemporary chimpanzees and baboons reveals a staunch avoidance of carrion due to the increased risk of internal parasites Ragir et al. Scavenging does become a plausible means of subsistence when cooking food is an option Ragir et al.

Based on these data, it is reasonable to suggest that some species of early hominid were hunting and consuming meat from small mammals, reptiles and birds, in a way similar to modern chimpanzees. However, stronger zoo-archaeological evidence for this behavior must be discovered before anything conclusive can be said about meat-consumption in early hominids. Much clearer evidence has emerged with respect to the plant component of australopith diets.

Stable isotope analyses have revealed that the australopithecines consumed a diet that was rich in C4 plants grasses, sedgesor animals that consumed C4 plants Sponheimer et al. While these data are intriguing, they are not able to directly address exactly which C4 resources were consumed by the australopithecines. Based on the preceding discussion of meat-consumption in early hominids, it is unlikely that the diet was largely meat-based, although C4 consuming animals could have contributed somewhat to the stable isotope values obtained.

It is much more likely that the carbon isotope data reflects plant resources consumed by early hominids. Some modern species of primate, several species of baboons in particular, also consume diets rich in C4 plants, specifically grasses Sponheimer et al. This type of diet, however, is relatively nutrient poor compared to the frugivorous diets of many modern ape species.

The possibility that australopithecines heavily exploited underground storage organs USOs has been discussed recently in the literature e. Laden and Wrangham, These USOs are relatively rich in nutrients and could, in part, account for the C4 component of early hominid diets. Although Paranthropus and Australopithecus exhibit similar carbon isotope values, it is unlikely that their diets were the same. Grine and Martin suggest that this increased enamel thickness was related directly to some functional dietary adaptation.

Furthermore, the mandible in Paranthropus was much more robust and the temporalis and masseter muscles were considerably larger Fleagle, These food items could potentially have come from C4 plants, so this hypothesis does not negate the stable isotope data.

This specimen demonstrates the immense size of the mandible and massive cheek teeth premolars and molars in Paranthropus. However, based on the evidence a mixed-mode of subsistence could be proposed for early hominids, with a high reliance on underground storage organs, complemented by other plant materials seeds, nuts, fruits and a small component of hunted game small mammals, reptiles and birds.

Paranthropus probably consumed more fibrous plant materials based on its dental morphological characteristics. For those interested in a more extensive examination of early hominid diet, consult the volume edited by Ungar Morphological analyses of skeletal remains become much more significant when they are placed within a broader environmental and ecological context.

The Late Pleistocene 3. Terrestrial paleoclimatic indices indicate that the climate changed from warm and wet to a more seasonal climate, which was cool and dry deMenocal and Bloemendal, This general trend began some time between 3. Analyses of sedimentation deposited in caves support these interpretations Partridge et al. Thus, it is difficult to determine exactly what ecological conditions were like when the australopithecines emerged in Africa. More extensive paleoecological analyses must be carried out with respect to this time period in order to better understand the origins of the australopithecines as a group.

Pollen analyses have been used fairly extensively to reconstruct the environmental context of early hominid sites e. An examination of the data obtained from pollen analyses reveals that there is no clear way to characterize the environment of early hominid sites. A high degree of variability exists with respect to ecological conditions at these sites. Plant ecosystems at early hominid sites range from subdesertic steppe to Afro-alpine heath moorland, but do not show any evidence of closed rainforest Bonnefille, This diversity in ecology and plant resources fits well with the generalized mixed-mode of subsistence presented earlier utilization of a wide variety of plant and animal resources for these early hominids.

For those interested in exploring paleoclimate and paleoecology further, consult the volume edited by Vrba et al.

Piltdown Man

Early studies of tool-manufacturing and tool-using capabilities of the early hominids were quite problematic. In southern Africa, Dart attributed a toolkit based on bone, teeth and horn to the australopithecines. In east Africa, the earliest documented stone tools of the Oldowan Industry, were initially attributed to Paranthropus boisei; however, this changed with the discovery of the more advanced Homo habilis, who was then heralded as the first stone tool maker in the hominid lineage Tobias, As more lithic evidence became available, this scenario quickly became untenable.

The Oldowan Industry is distributed throughout Africa and has recently been discovered in Europe in association with the recently discovered hominid remains in the Republic of Georgia Gabunia et al. The nature of the tools themselves is highly debatable. It was initially purported that the technology was based around large cores that were used as general purpose tools choppers and flakes removed from the cores that may have also been utilized as scrapers, burins or knives see Leakey, Both the flakes and cores are very simple in nature, involving minimal reduction to reach their final stage.

If one is not well-versed in early lithic technology, it is very easy to view these tools especially the cores as nothing more than rocks.

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For those wishing to see what these tools looked like, Leakey and Schick and Toth present very good illustrations of the Oldowan Industry. The cores were seen as the dominant tool-type of the Oldowan for many years. More recently, it has been suggested that the cores were really nothing more than byproducts of flake manufacture.

According to this view, it was the flakes that were the desired tool Toth, This is in much better accordance with what is known about the cognitive abilities of the australopithecines. The manufacture of a core tool involves a mental template for what that tool should look like and implies a degree of intelligence, which may have been beyond the australopithecines Toth, Conversely, flakes that are struck from a core and utilized require considerably less in terms of mental capabilities, and this is perhaps comparable to the amount of foresight required for a chimpanzee to select an appropriate branch for termite fishing or rock for nut-cracking.

The earliest Oldowan tools do not show any evidence of re-touching Semaw, and they were constructed of locally abundant materials Toth,indicating that hominids were not particularly selective in terms of raw materials.

This fits with an interpretation of little mental foresight in the early Oldowan toolmakers. Because of taphonomic processes, lithic technology is all that preserves from the Pliocene and Pleistocene.

However, this does not suggest that australopithecine technology consisted only of simple stone tools. Rather, it is very likely that the australopithecines utilized a wide variety of tools made of perishable materials such as digging sticks and probeswhat have been described as instruments by Oswalt These instruments are found in all toolkits of modern hunter-gatherer groups Torrenceand the use of these tools has been well documented in Pan troglodytes McGrew, Given the universality of these types of tools and the notion that Pan troglodytes is the best analogy for early hominid behavior McGrew,the australopithecines likely used wooden instruments fairly extensively, possibly for digging up USOs or immobilizing small animal prey.

Determining exactly what the earliest tools were used for is a difficult task to say the least. A number of potential uses have been proposed, including: However, butchery is the only one of these that leaves any visible evidence in the archaeological record. Nelson suggests that the items in a toolkit with few tool types the Oldowan would be a good example of this be versatile and flexible.

In other words, the few tool types that are present would be used in a wide variety of contexts. In this way, it is sensible to suggest that the australopithecines were utilizing these simple but versatile flake tools for a wide variety of tasks, including, but not limited to those mentioned above. It is notoriously difficult to directly correlate a stone tool technology with any particular species of hominid. Some have suggested that only Paranthropus made and used stone tools, and Australopithecus did not Fleagle, This seems unlikely though, given the distribution of stone tool bearing sites and the fact that many of them are not found in association with Paranthropus.

However, this is not to suggest that Paranthropus was not capable of manufacturing stone tools. Until more sites are found and better associations can be made between specific species of early hominid and lithic assemblages, it is unclear which species manufactured stone tools and which did not. Any and all species of australopithecine inhabiting the African landscape between 2. The most widely discussed hypothesis involves climatic change and a shift in resource availability around 2.

While this hypothesis has been relatively well-received see Plummer,it remains difficult to test with empirical archaeological evidence.

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There may be other extenuating factors which contributed to the development of the first stone tools. For those interested in more in-depth considerations of the earliest stone tools, there is a substantial amount of literature published on the subject.

More recently, Plummer provides a very good review of the development of the Oldowan. Map of Africa showing the distribution of several important sites. Generally, the australopithecines can be divided into two broad categories based on their dental characteristics: The traits that are used to differentiate these genera are summarized in Table 3 compiled from Fleagle, The following section will examine each species of australopithecine individually, focusing largely on the morphological characteristics of each species.

East Africa Kenya, Ethiopia Age: This species is largely known from teeth and fragmentary pieces of maxillae and mandibles; very limited postcranial material has been recovered Klein, However, important among these limited postcranial remains is the proximal end of a tibia, which demonstrates morphological characteristics that demonstrate A.

However, the humerus and radius of A. Additionally, it has been suggested that, based on the limited postcranial material available, A. The mandibular morphology of A.

The postcanine tooth rows are arranged essentially parallel to one another. This condition is present in Pan, but not in other species of hominid, who tend to have a much more parabolic arch in their dentition. Furthermore, the canines of A. Again, this condition is similar to that observed in Pan, but rare among the Hominidae. There are, however, several important traits that A. The enamel is quite thick, and the molars are large and broad Klein, Additional similarities to A.

However, given the lack of well-preserved A. Australopithecus afarensis Type Specimen: Distal end of the femur and proximal end of the tibia of Australopithecus afarensis A. The articulation between these two bones is almost identical to that of modern humans. This is largely due to the very famous and relatively complete female specimen A. This species is well-represented in the fossil record especially compared to A.

Thus, much more is known about its anatomy and behavior than earlier hominids. Although it was initially believed that A. However, this does not suggest that this species of hominid is in any way less significant.

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The cranium of A. The cranial morphology of this species is quite well known, based largely on three nearly complete specimens: The cranial capacity varies relatively widely in this species; this can be attributed to a high degree of sexual dimorphism.

Initially, the range of cranial capacity in A. This specimen had a particularly robust mandible, well-developed bony areas for attachment of the temporalis and masseter muscles and relatively large canine teeth Johanson and Edgar, This degree of sexual dimorphism is considerably greater than that observed in more recent hominids and modern humans, and is similar to the degree expressed in some extant great ape species.

Although the brain of A. The parietal cerebral cortex is markedly enlarged and exhibits a different type of organization than observed in apes, characteristics firmly associated with more recent hominids and modern humans Holloway, Due to the lack of complete cranial remains of earlier hominids it is presently unknown whether A.

The face of A. This contrasts sharply with most other australopithecines and especially with members of the genus Homo, all of whom possess relatively flat faces with considerably less sub-nasal prognathism.

The canines are quite large in this species and are considerably larger in males than females. This, combined with the high degree of body size sexual dimorphism may have important implications for social organization in this species, possibly reflecting intense male-male competition and a polygynous mating system, as was discussed previously.

This gap occurs due to the large size of the lower canine and is observed in modern great ape species, but not in other hominids Klein, Additionally, the tooth rows on the maxilla converge posteriorly Kimbel et al.

A recently discovered partial mandible from Chad is very similar to other specimens of A. However, additional fossil material must be recovered and examined before this specimen is designated as a separate species. Some have suggested that this specimen be lumped with A. Based on the wear patterns observed on the teeth of several A.

This suggestion seems reasonable. Stone tool use has not been documented at the time during which A. However, it is entirely possible that this species manufactured expedient tools of wood, grass or other organic materials in a fashion similar to modern chimpanzees; but, this cannot be demonstrated directly in the fossil record.

The postcranial skeleton of A. The femur is relatively short, the forearms appear to have been relatively long and very powerful, the phalanges of the hands and feet were curved and the morphology of the glenoid fossa on the scapula appears to have been more similar to modern chimpanzees Klein, All of these anatomical features indicate that A.

Much of what is known about the postcranial anatomy of A. Several important anatomical characteristics demonstrate the bipedality of A. All of these traits facilitate bipedal locomotion and are observed in modern humans, but not in the great apes.

Other, older, hominids such as Ardipithecus ramidus possess some, but not all of these key bipedal features. This is largely due to the relative completeness of the fossil record with respect to A. The evolutionary significance of these traits will be considered below.

Australopithecus africanus Type Specimen: Southern Africa South Africa Age: Woodward's argument ran as follows. All the remains in the gravel were found very close together-within a yard or so of each other.

The lower jaw and the brain-case were very similar in appearance. They were both of a similar brown color, and also apparently in the same state of fossilisation. The jaw, even though ape-like, did have some important human features, particularly in the teeth.

The molar teeth had apparently been worn to a flatness never seen in apes, and only to be expected if the jaw had belonged to a type of human being.


The roots [] of the teeth as seen in the X-ray pictures of the time were also much more like those of human teeth. And finally, the appearances of this ape-like man at the beginning of the Ice Age was just what many authorities had expected to find. In July a new specimen was found, a canine tooth, ape-like, but worn in a way never found in modern apes. This was strong support for Woodward's interpretation.

For all that, controversy continued to rage as to whether it was really correct to link the jaw and the brain-case. Miller in America and Prof. Boule in France-were not convinced. They could not see how anatomically the jaw could have worked as part of a human skull when it was constructed in so very different a way. But the opposition case was a good deal weaker than Woodward's. They could not explain the extraordinary wear of the teeth.

The opponents also had to explain the amazing coincidence of finding, in one place close together, a brain-case without a jaw, and a jaw without a brain-case, all apparently in the same state of preservation.

But they decided it was a coincidence, astonishing though it seemed. They maintained that there were two different fossils there, a fossil man, and a fossil ape, both of an extreme antiquity. But this view was dealt a severe blow when the remains of a second Piltdown Man were reported in as coming from a place about two miles away from the first site. Here again there were pieces of thick brain-case like those found at the original site, and with them a molar tooth, again similar to those in the jaw of the first Piltdown Man.

From now on Woodward's ideas held the field and most scientists agreed with.