Australopithecus sediba Australopithecus sediba Two spectacular new hominid fossils found in a cave at Malapa in South Africa in 2008 and 2009 have been assigned to a new species, Australopithecus sediba ('sediba' means 'wellspring' in the local seSotho language). Discovered by a team led by Lee Berger and Paul Dirks, it is claimed by them to be the best candidate yet for an immediate ancestor to the genus Homo. The fossils are between 1.78 and 1.95 million years old, about the same date of the oldest Homo erectus fossils. The first fossil, MH1, found by Lee Berger's son Matthew, is an almost complete skull and partial skeleton of an 11 to 12 year old boy. The second fossil, MH2, is a partial skeleton of an adult female, including some jaw fragments. The boy's brain has a typical australopithecine size of 420cc, compared to the smallest Homo brain of 510cc. Both skeletons are small, about 130cm (4'3") tall. Au.

sediba is most similar to, and quite likely descended from, Au. africanus. The upper limbs are long, and similar to other australopithecines. Many features of the hip, knee and ankle bones show it was bipedal, like other australopithecines, but the foot bones are still quite primitive. However Berger et al. list many other features of the skull, teeth, and pelvis in which it resembles early Homo fossils. The discoverers have suggested that Au. sediba might be ancestral to either Homo habilis or Homo rudolfensis, or that it might be a closely related sister group to Homo - not a direct ancestor, but a close cousin. Anatomically sediba would be a plausible Homo ancestor, but as the authors admit, these two individuals existed after the earliest known Homo fossils (at about 2.3 million years), so they can't be human ancestors. However, it's not impossible that the sediba species had already existed for a few hundred thousand years and that early members of it could have been human ancestors.

Interestingly, prominent scientists quoted in the media have split fairly evenly on the question of whether sediba should have been assigned to Homo or Australopithecus - Bill Kimbel, Don Johanson, Susan Anton and Colin Groves went for Homo, while Meave Leakey, Tim White and Ron Clarke didn't. Some scientists have even suggested that it may be a late-surviving variant of Au. africanus. However, the authors argued that the overall body plan was australopithecine, and hence put it in that genus. This seems to be the conservative and safest plan; even if they are right in their claims about sediba, the fossils do not seem out of place in Australopithecus, whereas putting them in Homo would have run the risk of needing to reclassify them later if they did not turn out to be very closely related to Homo. It would also, as Chris Stringer pointed out in an interview, require "a major redefinition" of the genus Homo. In summary, it's an important discovery even though we don't yet know exactly how it fits into the family tree and what it means for human origins.

Refreshingly, the discoverers have been fairly restrained in their claims about the fossil, and are keeping other options in mind. The creationist response The creationist organization Answers In Genesis has already taken note of the fossil . One might have expected that such small, and small-brained, fossils would be dismissed as apes. A few years ago, I'm sure AIG would have done so unhesitatingly. But AIG has strongly backed the idea that the similarly-sized Hobbit from Flores is a pathological human. Because of that, and probably also because some scientists have said Au. sediba should have been classified as Homo, AIG was surprisingly cautious. After referring to a quote by Berger that the small brain size of sediba (an australopithecine feature) is similar to that of the Flores Hobbit, AIG says that: Berger's comment suggests the Australopithecus sediba fossils may in fact be misclassified Homo individuals who were fully human. and But whatever happened to this earlier claim by AIG : When complete fossils are found, they are easy to assign clearly as either 'ape' or human, there are only 'ape-men' where imagination colored by belief in evolution is applied to fragmented bits and pieces.

What happened to it is that creationists have been burned by reality: there are too many cases where creationists have classified fossils differently, and even cases of creationists changing their mind about some fossils. In spite of there being an almost complete skull of sediba, AIG still can't decide whether it's an ape or a human. If they can't tell if it's an ape or a human, they obviously can't rule out the possibility that it is an intermediate. The fact that they can't tell is strong evidence that it is intermediate, because modern apes and humans are extremely easy to distinguish. Brian Thomas of the Institute for Creation Research also wrote about sediba . Unlike AIG, ICR had no hesitation in calling it an ape. Thomas even disputes the claim that sediba was bipedal, saying ... in neither A. ramidus' nor Au sediba's remains were found the relevant hip bones to even make such a determination! Odd. MH1 has a good specimen of the os coxa bone, more commonly known as "the hip bone", which is, funnily enough, the "relevant hip bone" for diagnosing locomotion. And let's not forget that Berger et al.

said that the hip, knee and ankle bones all show evidence of bipedality. I think the experts have a bit more credibility here than the ICR's science writer. Another creationist to have written about Au. sediba is Todd Wood, whose Baraminological analysis places sediba, along with H. habilis and H. rudolfensis, among humans. Other creationists are not going to like that result, because sediba is far more similar to africanus or afarensis (Lucy) than it is to modern humans. If you take it as an article of faith that human evolution didn't happen and that classifying hominids is merely a matter of working out how best to divide them into apes and humans (and that is almost always the creationist approach), then it really is a no-brainer to classify sediba as an ape (I'm sure AIG will come to that conclusion soon too). I'm impressed by Wood's integrity in accepting his conclusion rather than tweaking his analysis until he got a more convenient result, because it is going to be very difficult to reconcile with creationism. If you invite sediba into the human family, then what's to stop africanus and Lucy joining as well?

One last gripe: it was depressing to see how many newspaper headlines used the term "missing link". It's a misleading and meaningless term, as Carl Zimmer explains well . Hominid Species Hominid Species Introduction Hominid or hominin? Some scientists use a broader definition of Hominidae which includes the great apes, and instead call the group I am discussing "hominins". For a good discussion of the hominid/hominin terminology issue, read this article by Lee Berger. The word "hominid" in this website refers to members of the family of humans, Hominidae, which consists of all species on our side of the last common ancestor of humans and living apes. Hominids are included in the superfamily of all apes, the Hominoidea, the members of which are called hominoids. Although the hominid fossil record is far from complete, and the evidence is often fragmentary, there is enough to give a good outline of the evolutionary history of humans. The time of the split between humans and living apes used to be thought to have occurred 15 to 20 million years ago, or even up to 30 or 40 million years ago.

Some apes occurring within that time period, such as Ramapithecus, used to be considered as hominids, and possible ancestors of humans. Later fossil finds indicated that Ramapithecus was more closely related to the orang-utan, and new biochemical evidence indicated that the last common ancestor of hominids and apes occurred between 5 and 10 million years ago, and probably in the lower end of that range (Lewin 1987). Ramapithecus therefore is no longer considered a hominid. The field of science which studies the human fossil record is known as paleoanthropology. It is the intersection of the disciplines of paleontology (the study of ancient lifeforms) and anthropology (the study of humans). Hominid Species The species here are listed roughly in order of appearance in the fossil record (note that this ordering is not meant to represent an evolutionary sequence), except that the robust australopithecines are kept together. Each name consists of a genus name (e.g. Australopithecus, Homo) which is always capitalized, and a specific name (e.g. africanus, erectus) which is always in lower case.

Within the text, genus names are often omitted for brevity. Each species has a type specimen which was used to define it. Sahelanthropus tchadensis This species was named in July 2002 from fossils discovered in Chad in Central Africa (Brunet et al. 2002, Wood 2002). It is the oldest known hominid or near-hominid species , dated at between 6 and 7 million years old. This species is known from a nearly complete cranium nicknamed Toumai , and a number of fragmentary lower jaws and teeth. The skull has a very small brain size of approximately 350 cc. It is not known whether it was bipedal. S. tchadensis has many primitive apelike features, such as the small brainsize, along with others, such as the brow ridges and small canine teeth, which are characteristic of later hominids. This mixture, along with the fact that it comes from around the time when the hominids are thought to have diverged from chimpanzees, suggests it is close to the common ancestor of humans and chimpanzees.

Orrorin tugenensis This species was named in July 2001 from fossils discovered in western Kenya (Senut et al. 2001). The fossils include fragmentary arm and thigh bones, lower jaws, and teeth and were discovered in deposits that are about 6 million years old. The limb bones are about 1.5 times larger than those of Lucy, and suggest that it was about the size of a female chimpanzee. Its finders have claimed that Orrorin was a human ancestor adapted to both bipedality and tree climbing, and that the australopithecines are an extinct offshoot. Given the fragmentary nature of the remains, other scientists have been skeptical of these claims so far (Aiello and Collard 2001). A later paper (Galik et al. 2004) has found further evidence of bipedality in the fossil femur. Ardipithecus ramidus This species was named Australopithecus ramidus in September 1994 (White et al. 1994; Wood 1994) from some fragmentary fossils dated at 4.4 million years.

A more complete skull and partial skeleton was discovered in late 1994 and based on that fossil, the species was reallocated to the genus Ardipithecus (White et al. 2005). This fossil was extremely fragile, and excavation, restoration and analysis of it took 15 years. It was published in October 2009, and given the nickname 'Ardi' . Ar. ramidus was about 120 cm (3'11") tall and weighed about 50 kg (110 lbs). The skull and brain are small, about the size of a chimpanzee. It was bipedal on the ground, though not as well adapted to bipedalism as the australopithecines were, and quadrupedal in the trees. It lived in a woodland environment with patches of forest, indicating that bipedalism did not originate in a savannah environment.

A number of fragmentary fossils discovered between 1997 and 2001, and dating from 5.2 to 5.8 million years old, were originally assigned to a new subspecies, Ardipithecus ramidus kadabba (Haile-Selassie 2001), and later to a new species, Ardipithecus kadabba (Haile-Selassie et al. 2004). One of these fossils is a toe bone belonging to a bipedal creature, but is a few hundred thousand years younger than the rest of the fossils and so its identification with kadabba is not as firm as the other fossils. Australopithecus anamensis This species was named in August 1995 (Leakey et al. 1995). The material consists of 9 fossils, mostly found in 1994, from Kanapoi in Kenya, and 12 fossils, mostly teeth found in 1988, from Allia Bay in Kenya (Leakey et al. 1995).

Anamensis existed between 4.2 and 3.9 million years ago, and has a mixture of primitive features in the skull, and advanced features in the body. The teeth and jaws are very similar to those of older fossil apes. A partial tibia (the larger of the two lower leg bones) is strong evidence of bipedality, and a lower humerus (the upper arm bone) is extremely humanlike. Note that although the skull and skeletal bones are thought to be from the same species, this is not confirmed. Australopithecus afarensis A. afarensis existed between 3.9 and 3.0 million years ago. Afarensis had an apelike face with a low forehead, a bony ridge over the eyes, a flat nose, and no chin. They had protruding jaws with large back teeth. Cranial capacity varied from about 375 to 550 cc. The skull is similar to that of a chimpanzee, except for the more humanlike teeth.

The canine teeth are much smaller than those of modern apes, but larger and more pointed than those of humans, and shape of the jaw is between the rectangular shape of apes and the parabolic shape of humans. However their pelvis and leg bones far more closely resemble those of modern man , and leave no doubt that they were bipedal (although adapted to walking rather than running (Leakey 1994)). Their bones show that they were physically very strong. Females were substantially smaller than males, a condition known as sexual dimorphism. Height varied between about 107 cm (3'6") and 152 cm (5'0"). The finger and toe bones are curved and proportionally longer than in humans, but the hands are similar to humans in most other details (Johanson and Edey 1981). Most scientists consider this evidence that afarensis was still partially adapted to climbing in trees, others consider it evolutionary baggage. Kenyanthropus platyops This species was named in 2001 from a partial skull found in Kenya with an unusual mixture of features (Leakey et al. 2001).

It is aged about 3.5 million years old. The size of the skull is similar to A. afarensis and A. africanus, and has a large, flat face and small teeth. Australopithecus africanus A. africanus existed between 3 and 2 million years ago. It is similar to afarensis, and was also bipedal , but body size was slightly greater. Brain size may also have been slightly larger, ranging between 420 and 500 cc. This is a little larger than chimp brains (despite a similar body size), but still not advanced in the areas necessary for speech. The back teeth were a little bigger than in afarensis. Although the teeth and jaws of africanus are much larger than those of humans, they are far more similar to human teeth than to those of apes (Johanson and Edey 1981). The shape of the jaw is now fully parabolic, like that of humans, and the size of the canine teeth is further reduced compared to afarensis.

Australopithecus garhi This species was named in April 1999 (Asfaw et al. 1999). It is known from a partial skull . The skull differs from previous australopithecine species in the combination of its features, notably the extremely large size of its teeth, especially the rear ones, and a primitive skull morphology. Some nearby skeletal remains may belong to the same species. They show a humanlike ratio of the humerus and femur, but an apelike ratio of the lower and upper arm. ( Groves 1999 ; Culotta 1999) Australopithecus sediba A. sediba was discovered at the site of Malapa in South Africa in 2008. Two partial skeletons were found, of a young boy and an adult female, dated between 1.78 and 1.95 million years ago (Berger et al. 2010, Balter 2010). It is claimed by its finders to be transitional between A.

africanus and Homo and, because it is more similar to Homo than any other australopithecine, a possible candidate for the ancestor of Homo. A. sediba was bipedal with long arms suitable for climbing, but had a number of humanlike traits in the skull, teeth and pelvis. The boy's skull has a volume of 420 cc, and both fossils are short, about 130 cm (4'3"). Australopithecus afarensis and africanus, and the other species above, are known as gracile australopithecines, because their skulls and teeth are not as large and strong as those of the following species, which are known as the robust australopithecines. (Gracile means "slender", and in paleoanthropology is used as an antonym to "robust".) Despite this, they were still more robust than modern humans. Australopithecus aethiopicus A. aethiopicus existed between 2.6 and 2.3 million years ago.

This species is known from one major specimen, the Black Skull discovered by Alan Walker, and a few other minor specimens which may belong to the same species. It may be an ancestor of robustus and boisei, but it has a baffling mixture of primitive and advanced traits. The brain size is very small, at 410 cc, and parts of the skull, particularly the hind portions, are very primitive, most resembling afarensis. Other characteristics, like the massiveness of the face, jaws and single tooth found, and the largest sagittal crest in any known hominid, are more reminiscent of A. boisei (Leakey and Lewin 1992). (A sagittal crest is a bony ridge on top of the skull to which chewing muscles attach.) Australopithecus robustus A. robustus had a body similar to that of africanus, but a larger and more robust skull and teeth. It existed between 2 and 1.5 million years ago. The massive face is flat or dished, with no forehead and large brow ridges. It has relatively small front teeth, but massive grinding teeth in a large lower jaw. Most specimens have sagittal crests.

Its diet would have been mostly coarse, tough food that needed a lot of chewing. The average brain size is about 530 cc. Bones excavated with robustus skeletons indicate that they may have been used as digging tools. Australopithecus boisei (was Zinjanthropus boisei) A. boisei existed between 2.1 and 1.1 million years ago. It was similar to robustus, but the face and cheek teeth were even more massive, some molars being up to 2 cm across. The brain size is very similar to robustus, about 530 cc. A few experts consider boisei and robustus to be variants of the same species. Australopithecus aethiopicus, robustus and boisei are known as robust australopithecines, because their skulls in particular are more heavily built. They have never been serious candidates for being direct human ancestors. Many authorities now classify them in the genus Paranthropus. Homo habilis H. habilis, "handy man", was so called because of evidence of tools found with its remains.

Habilis existed between 2.4 and 1.5 million years ago. It is very similar to australopithecines in many ways. The face is still primitive, but it projects less than in A. africanus. The back teeth are smaller, but still considerably larger than in modern humans. The average brain size, at 650 cc, is considerably larger than in australopithecines. Brain size varies between 500 and 800 cc, overlapping the australopithecines at the low end and H. erectus at the high end. The brain shape is also more humanlike. The bulge of Broca's area, essential for speech, is visible in one habilis brain cast, and indicates it was possibly capable of rudimentary speech . Habilis is thought to have been about 127 cm (5'0") tall, and about 45 kg (100 lb) in weight, although females may have been smaller. Habilis has been a controversial species. Originally, some scientists did not accept its validity, believing that all habilis specimens should be assigned to either the australopithecines or Homo erectus.

H. habilis is now fully accepted as a species, but it is widely thought that the 'habilis' specimens have too wide a range of variation for a single species, and that some of the specimens should be placed in one or more other species. One suggested species which is accepted by many scientists is Homo rudolfensis, which would contain fossils such as ER 1470 . Homo georgicus This species was named in 2002 to contain fossils found in Dmanisi, Georgia, which seem intermediate between H. habilis and H. erectus. The fossils are about 1.8 million years old, consisting of three partial skulls and three lower jaws. The brain sizes of the skulls vary from 600 to 780 cc. The height, as estimated from a foot bone, would have been about 1.5 m (4'11"). A partial skeleton was also discovered in 2001 but no details are available on it yet. (Vekua et al. 2002, Gabunia et al. 2002) Homo erectus H.

erectus existed between 1.8 million and 300,000 years ago. Like habilis, the face has protruding jaws with large molars, no chin, thick brow ridges, and a long low skull, with a brain size varying between 750 and 1225 cc. Early erectus specimens average about 900 cc, while late ones have an average of about 1100 cc (Leakey 1994). The skeleton is more robust than those of modern humans, implying greater strength. Body proportions vary; the Turkana Boy is tall and slender (though still extraordinarily strong), like modern humans from the same area, while the few limb bones found of Peking Man indicate a shorter, sturdier build. Study of the Turkana Boy skeleton indicates that erectus may have been more efficient at walking than modern humans, whose skeletons have had to adapt to allow for the birth of larger-brained infants (Willis 1989). Homo habilis and all the australopithecines are found only in Africa, but erectus was wide-ranging, and has been found in Africa, Asia, and Europe.

There is evidence that erectus probably used fire , and their stone tools are more sophisticated than those of habilis. Homo ergaster Some scientists classify some African erectus specimens as belonging to a separate species, Homo ergaster, which differs from the Asian H. erectus fossils in some details of the skull (e.g. the brow ridges differ in shape, and erectus would have a larger brain size). Under this scheme, H. ergaster would include fossils such as the Turkana boy and ER 3733 . Homo sapiens (archaic) (also Homo heidelbergensis) Archaic forms of Homo sapiens first appear about 500,000 years ago. The term covers a diverse group of skulls which have features of both Homo erectus and modern humans. The brain size is larger than erectus and smaller than most modern humans, averaging about 1200 cc, and the skull is more rounded than in erectus. The skeleton and teeth are usually less robust than erectus, but more robust than modern humans. Many still have large brow ridges and receding foreheads and chins.

There is no clear dividing line between late erectus and archaic sapiens, and many fossils between 500,000 and 200,000 years ago are difficult to classify as one or the other. Homo sapiens neanderthalensis (also Homo neanderthalensis) Neandertal ( or Neanderthal ) man existed between 230,000 and 30,000 years ago. The average brain size is slightly larger than that of modern humans, about 1450 cc, but this is probably correlated with their greater bulk. The brain case however is longer and lower than that of modern humans, with a marked bulge at the back of the skull. Like erectus, they had a protruding jaw and receding forehead. The chin was usually weak. The midfacial area also protrudes, a feature that is not found in erectus or sapiens and may be an adaptation to cold. There are other minor anatomical differences from modern humans, the most unusual being some peculiarities of the shoulder blade, and of the pubic bone in the pelvis.

Neandertals mostly lived in cold climates, and their body proportions are similar to those of modern cold-adapted peoples: short and solid, with short limbs. Men averaged about 168 cm (5'6") in height. Their bones are thick and heavy, and show signs of powerful muscle attachments. Neandertals would have been extraordinarily strong by modern standards, and their skeletons show that they endured brutally hard lives . A large number of tools and weapons have been found, more advanced than those of Homo erectus. Neandertals were formidable hunters, and are the first people known to have buried their dead, with the oldest known burial site being about 100,000 years old. They are found throughout Europe and the Middle East. Western European Neandertals usually have a more robust form, and are sometimes called "classic Neandertals". Neandertals found elsewhere tend to be less excessively robust. (Trinkaus and Shipman 1992; Trinkaus and Howells 1979; Gore 1996) Homo sapiens sapiens (modern) Modern forms of Homo sapiens first appear about 195,000 years ago.

Modern humans have an average brain size of about 1350 cc. The forehead rises sharply, eyebrow ridges are very small or more usually absent, the chin is prominent, and the skeleton is very gracile. About 40,000 years ago, with the appearance of the Cro-Magnon culture, tool kits started becoming markedly more sophisticated , using a wider variety of raw materials such as bone and antler, and containing new implements for making clothing, engraving and sculpting. Fine artwork, in the form of decorated tools, beads, ivory carvings of humans and animals, clay figurines, musical instruments, and spectacular cave paintings appeared over the next 20,000 years. (Leakey 1994) Even within the last 100,000 years, the long-term trends towards smaller molars and decreased robustness can be discerned. The face, jaw and teeth of Mesolithic humans (about 10,000 years ago) are about 10% more robust than ours.

Upper Paleolithic humans (about 30,000 years ago) are about 20 to 30% more robust than the modern condition in Europe and Asia. These are considered modern humans, although they are sometimes termed "primitive". Interestingly, some modern humans (aboriginal Australians) have tooth sizes more typical of archaic sapiens. The smallest tooth sizes are found in those areas where food-processing techniques have been used for the longest time. This is a probable example of natural selection which has occurred within the last 10,000 years (Brace 1983). This diagram shows roughly the time range in which each hominid species lived: This page is part of the Fossil Hominids FAQ at the talk.origins Archive . New Species of Hominid Skeleton Found in South Africa - TIME Follow @TIME Evolution skeptics like to trot out the argument that if Darwin had been right, scientists would have discovered transitional fossils by now  creatures with a mix of features from earlier and later species. Since they haven't, the deniers say, evolution must not be true. The truth is that paleontologists have found transitional species by the score, from many different time periods.

But none have materialized from as crucial a point in our evolutionary past as a pair of skeletons whose discovery was announced today by the journal Science. (See the top 10 scientific discoveries of 2009.) The fossils, which have been determined to be of a new species, Australopithecus sediba, were found by Matthew Berger, the 9-year-old son of paleontologist Lee Berger, of South Africa's University of the Witwatersrand. (The elder Berger tried in vain to get the editors of Science to list Matthew as a co-author of the paper.) The bones belong to a preteenage boy and a woman estimated to have been in her late 20s or early 30s; the individuals died at about the same time, and before their remains had fully decomposed, they were entombed in an avalanche of sediment and were nearly perfectly preserved deep in the Malapa cave north of Johannesburg. The Au. sediba bones are important for their vintage  they date back to the moment about 2 million years ago when the genus of human ancestors known as Australopithecus was just giving way to a new group called Homo, which would eventually produce Homo sapiens, or modern humans.

(See the top 10 animal stories of 2009.) But the new find is perhaps most astonishing for its state of preservation. "These are arguably the most complete hominid skeletons ever discovered," says Berger. In the field of human origins, that's huge: many human ancestors have been identified based on only a few bone fragments, and even Berger's rivals in the intensely competitive field of human paleontology were quick to praise his discovery. "This is an outstanding find, and Lee should really be congratulated," says Meave Leakey, a paleontologist with the National Museums of Kenya and a member of the world's most celebrated fossil-hunting family. Other paleontologists have confirmed the dating of the skeletons to somewhere between 1.95 million and 1.78 million years ago, which is another crucial clue to figuring out the new species' place in our evolutionary story. That's where things get a lot more contentious. The skeletons show a remarkable mix of primitive and advanced features. The arms, for example, are relatively long and apelike, suggesting Au. sediba was a prodigious tree climber.

The hands are apelike in their curvature but surprisingly compact, like a more modern hominid's. And the longer legs and shortened pelvis are decidedly modern. "They were competent bipeds on the ground," says Berger. The boy's skull is a similar mashup of older and newer features. (The woman's skull is missing.) It is quite small  "like a pinhead on top of the body," said Berger at a teleconference on Wednesday, April 7  and would have held a brain hardly bigger than that of Australopithecus afarensis, the 3.2 millionyear-old species whose best-known example is the celebrated Lucy. But many of the boy's facial features  a prominent nose, relatively small molars and less pronounced cheekbones  look more like those of later Homo species. As to exactly where Au. sediba fits in human evolution, Berger offers two possibilities: First, it could represent some sort of evolutionary dead end, a species that came and went and had nothing directly to do with modern humans. "It's like we're seeing some experiment going on," he says.

Or  and this is the idea he favors  it could be the direct ancestor of Homo erectus, which most paleontologists agree is the direct ancestor of Homo sapiens. Indeed, Berger's colleagues had initially planned to assign the new species to Homo but changed their minds, given the specimens' long arms and the boy's small brain. "This may be a Rosetta stone for defining what the genus Homo really is," says Berger. It is at this point that Berger's claims start to meet a lot of resistance. Leakey, for one, thinks the new species is at best an evolutionary cousin of our ancestors and not a direct ancestor of the species that eventually gave rise to Homo sapiens. Tim White, a paleontologist at the University of California, Berkeley, whose team recently discovered a 4.4 millionyear-old skeleton of Ardipithecus ramidus , also believes Au. sediba bears no relationship to modern humans. White points out that drawing strong conclusions about a species based on such a young individual as the fossilized boy is risky, because the skeleton would have still been developing.

"The obsession with Homo in their [paper's] title and text is difficult to understand outside of a media context," White says, referring to the Science study that describes the new species as "Homo-like." But other paleontologists are inclined to agree with Berger. William Kimbel of Arizona State University's Institute of Human Origins says Berger's paper makes the case that the specimens show early evidence of Homo. More important, Kimbel says, the fossils reveal the pace of change in early human ancestors. "What it tells us about the early stage of the Homo lineage is, for example, that there were already substantial changes in the face, the teeth and the pelvis, while the brain size and limb proportions were still reasonably limited," he says. "Having that calendar of change allows us to pose questions about what forces were driving that calendar." More questions  and answers  will likely arise as Berger and his team continue studying the South African site. They are already in the process of excavating two more fossils, including a second adult woman and a baby. And Berger has brought in what he calls "the best reconstructors in the world" to re-create what the boy's face would have looked like.

"We'll be telling you a lot more about the species as time goes on," he says. The team has also found numerous bones of animals, including remnants of saber-toothed cats, that lived alongside the hominids. "The quality of site means I won't have to speculate much at all about the environment they inhabited or the animals they lived with," he says. Lastly, Berger suggests the tantalizing possibility of testing the fossils' DNA. Although the oldest DNA paleontologists have successfully recovered so far dates back only tens of thousands of years, Berger said at a press conference, "We have states of preservation here that are truly extraordinary." But is it even possible to retrieve 2 millionyear-old DNA?

It's a long shot, he says, "but we're treating it as though maybe it could be preserved."  Reported by Alex Perry / Capetown Australopithecus sediba and the creationist response Australopithecus sediba and the creationist response By Jim Foley April 27, 2010 07:40 MST Two spectacular new hominid fossils found in a cave at Malapa in South Africa in 2008 and 2009 have been assigned to a new species, Australopithecus sediba (‘sediba’ means ‘wellspring’ in the local seSotho language). Discovered by a team led by Lee Berger and Paul Dirks, it is claimed by them to be the best candidate yet for an immediate ancestor to the genus Homo. The fossils are between 1.78 and 1.95 million years old, about the same date of the oldest Homo erectus fossils. The first fossil, MH1, found by Lee Berger’s son Matthew, is an almost complete skull and partial skeleton of an 11 to 12 year old boy.

The 2nd fossil, MH2, is a partial skeleton of an adult female, including some jaw fragments. The boy’s brain has a typical australopithecine size of 420cc, compared to the smallest Homo brain of 510cc. Both skeletons are small, about 130cm (4’3”) tall. Au. sediba is most similar to, and quite likely descended from, Au. africanus. The upper limbs are long, and similar to other australopithecines. Many features of the hip, knee and ankle bones show it was bipedal, like other australopithecines, but the foot bones are still quite primitive. However Berger et al. list many other features of the skull, teeth, and pelvis in which it resembles early Homo fossils. The discoverers have suggested that Au. sediba might be ancestral to either Homo habilis or Homo rudolfensis, or that it might be a closely related sister group to Homo - not a direct ancestor, but a close cousin. As the authors admit, these two individuals existed after the earliest known Homo fossils (at about 2.3 million years), so they can’t be human ancestors.

However, it’s possible that the sediba species had already existed for a few hundred thousand years and that early members of it could have been human ancestors. Interestingly, prominent scientists quoted in the media have split fairly evenly on the question of whether sediba should have been assigned to Homo or Australopithecus - Bill Kimbel, Don Johanson, Susan Anton and Colin Groves went for Homo, while Meave Leakey, Tim White and Ron Clarke didn’t. Some scientists have even suggested that it may be a late-surviving variant of Au. africanus. However, the authors argued that the overall body plan was australopithecine, and hence put it in that genus. This seems to be the conservative and safest plan; even if they are right in their claims about sediba, the fossils do not seem out of place in Australopithecus, whereas putting them in Homo would have run the risk of needing to reclassify them later if they did not turn out to be very closely related to Homo. It would also, as Chris Stringer pointed out in an interview, require “a major redefinition” of the genus Homo.

In summary, it’s an important discovery even though we don’t yet know exactly how it fits into the family tree and what it means for human origins. Refreshingly, the discoverers have been fairly restrained in their claims about the fossil, and are keeping other options in mind. The creationist organization Answers in Genesis has already taken note of the fossil . One might have expected that such small, and small-brained, fossils would be dismissed as apes. A few years ago, I’m sure AIG would have done so unhesitatingly. But AIG has strongly backed the idea that the similarly-sized Hobbit from Flores is a pathological human. Because of that, and probably also because some scientists have said Au. sediba should have been classified as Homo, AIG was surprisingly cautious. After referring to a quote by Berger that the small brain size of sediba (an australopithecine feature) is similar to that of the Flores Hobbit, AIG says that: Berger’s comment suggests the Australopithecus sediba fossils may in fact be misclassified Homo individuals who were fully human.

and But whatever happened to this earlier claim by AIG : When complete fossils are found, they are easy to assign clearly as either ‘ape’ or human, there are only ‘ape-men’ where imagination colored by belief in evolution is applied to fragmented bits and pieces. What happened to it is that creationists have been slapped around by reality: there are too many cases where creationists have classified fossils differently, and even cases of creationists changing their mind about some fossils. In spite of having an almost complete skull of sediba, AIG still can’t decide whether it’s an ape or a human. If they can’t tell if it’s an ape or a human, they obviously can’t rule out the possibility that it is an intermediate. The fact that they can’t tell is strong evidence that it is intermediate, because modern apes and humans are extremely easy to distinguish. Brian Thomas of the Institute for Creation Research has also written about sediba . Unlike AIG however, ICR had no hesitation in calling it an ape. Thomas even disputes the claim that sediba was bipedal, saying … in neither A. ramidus’ nor Au sediba’s remains were found the relevant hip bones to even make such a determination! Odd.

MH1 has a good specimen of the os coxa bone, more commonly known as “the hip bone”, which is, funnily enough, the “relevant hip bone” for diagnosing locomotion. And let’s not forget that Berger et al. said that the hip, knee and ankle bones all show evidence of bipedality. I think the experts have a bit more credibility here than the ICR’s science writer. One last gripe: it was depressing to see how many newspaper headlines used the term “missing link”. It’s a misleading and meaningless term, as Carl Zimmer explains well . Update: See also this later Panda’s Thumb blog entry by Nick Matzke: Creationist vs. creationist on Homo habilis . References Learn and talk about Australopithecus sediba, 2010 in paleontology, Australopithecus, Fossil taxa described in 2010, Pleistocene primates Berger et al., 2010 [1] Australopithecus sediba is a species of Australopithecus of the early Pleistocene , identified based on fossil remains dated to about 2 million years ago.

The species is known from six skeletons discovered in the Malapa Fossil Site at the Cradle of Humankind World Heritage Site in South Africa , including a juvenile male (MH1 also called "Karabo", [2] the holotype ), an adult female (MH2, the paratype ), an adult male, and three infants. [1] [3] The fossils were found together at the bottom of the Malapa Cave, where they apparently fell to their death, and have been dated to between 1.980 and 1.977 million years ago. [4] [5] Over 220 fragments from the species have been recovered to date. [1] The partial skeletons were initially described in two papers in the journal Science by American and South African palaeo-anthropologist Lee R. Berger from the University of the Witwatersrand , Johannesburg and colleagues as a newly discovered species of early human ancestor called Australopithecus sediba ("sediba" meaning "natural spring" or "well" in the Sotho language ).

[1] MH1 is disarticulated and 34% complete if skeletal elements known to be in an unprepared block are included (59.6% if small elements are excluded) while MH2 is 45.6% complete (again 59.6% excluding small elements) and exhibits partial articulation. [6] Australopithecus sediba may have lived in savannas but ate fruit and other foods from the forest —behavior similar to modern-day savanna chimpanzees . The conditions in which the individuals were buried and fossilized were extraordinary, permitting the extraction of plant phytoliths from dental plaque . [7] [8] [9] Contents Also see: Human timeline & Nature timeline Matthew Berger displaying the fossil he found on the Malapa Nature Reserve. The first specimen of A. sediba was found by paleoanthropologist Lee Berger 's nine-year-old son, Matthew, on August 15, 2008. [10] While exploring near his father's dig site in the dolomitic hills north of Johannesburg , on the Malapa Nature Reserve, Matthew stumbled upon a fossilized bone.

[10] The boy alerted his father to the find, who could not believe what he saw — a hominid clavicle . Upon turning the block over, "sticking out of the back of the rock was a mandible with a tooth, a canine , sticking out. And I almost died", he later recalled. [10] The fossil turned out to belong to a 4 ft 2 in (1.27 m) juvenile male, whose skull was discovered in March 2009 by Berger's team. [10] The find was announced to the public on April 8, 2010. Also found at the Malapa archeological site were a variety of animal fossils, including saber-toothed cats , mongooses , and antelopes . [10] Berger and geologist Paul Dirks speculated that the animals might have fallen into a deep 100–150-foot (30–46 m) "death-trap", perhaps lured by the scent of water. [10] The bodies may have then been swept into a pool of water with a sandy bottom and rich with lime , allowing the remains to become fossilized.

[10] Age estimates[ edit ] The fossil was dated using a combination of palaeomagnetism and uranium-lead (U-Pb) dating which showed that the fossils are no older than ~2.0 Ma. The presence of animal species which became extinct at ~1.5 Ma indicates the deposit is no younger than 1.5 Ma. The sediments have a 'normal' magnetic polarity and the only major period between 2.0 and 1.5 Ma when this occurred is the Olduvai sub-Chron between 1.95 and 1.78 Ma. [5] Accordingly, the fossils were originally dated to ~1.95 Ma. Recent dating of a capping flowstone demonstrated this was not possible and the normal magnetic polarity sediments have since been correlated to the 3000-year-long Pre-Olduvai event at ~1.977 Ma. Morphology and interpretations[ edit ] Because of the wide range of mosaic features exhibited in both cranial and post-cranial morphology, the authors suggest that A. sediba may be a transitional species between the southern African A. africanus (the Taung Child , Mrs.

Ples ) and either Homo habilis or even the later H. erectus ( Turkana boy , Java man , Peking man ). [1] A reconstruction of the skull of A. sediba holotype MH1, or Karabo. The cranial capacity of MH1, which has been estimated to be at 95% of adult capacity (420 cm3), is at the higher end of the range for A. africanus and far from the lower range of early Homo (631 cm3), but the mandible and tooth size are quite gracile and similar to what one would expect to find in H. erectus; so similar are these features that, if found in isolation without other skeletal remains, they could be classified as Homo based on tooth and mandible size. However, the cusp spacing is more like Australopithecus. Regardless of whether Australopithecus sediba is a direct ancestor of early Homo or not, our understanding of the range of variation in early hominins has been greatly increased with the finding of these new specimens. A. sediba compared to its ancestor species A. africanus on the whole is described by Berger et al.

as more derived towards Homo than A. garhi , especially showing a number of synapomorphies taken to anticipate the reorganization of the pelvis in H. erectus, associated with "more energetically efficient walking and running". The femur and tibia are fragmentary, but the foot combines an advanced anklebone combined with a primitive heel. [11] Its cranial capacity is estimated at around 420–450 cm3 (26–27 cu in), [1] about one-third that of modern humans . Palmar view of the hand and forearm of A. sediba paratype MH2. A. sediba had a surprisingly modern hand, whose precision grip suggests it might have been another tool-making Australopithecus. Evidence of the precision gripping and stone tool production can be seen from Homo-like features such as having a long thumb and short fingers. [12] [13] The nearly complete wrist and hand of an adult female from Malapa, South Africa presents Australopithecus-like features, such as a strong flexor apparatus associated with arboreal locomotion . [12] A well-preserved and articulated ankle of A.

sediba is mostly humanlike in form and function and possesses some evidence for a humanlike arch and Achilles tendon . However, A. sediba is apelike in possessing a more gracile calcaneal body and a more robust medial malleolus than expected. This shows that A. sediba may have practiced a unique combination of bipedalism and arboreality . [14] As opposed to the authors of the initial description, who interpreted both fossils as a possible transitional species between Australopithecus and Homo, other palaeoanthropologists are reluctant to do so. In an accompanying news article published with the initial descriptions in 2010, detractors of the idea that A. sediba might be ancestral to the genus Homo (e.g. Tim White and Ron Clarke ) suggest that the fossils could be a late southern African branch of Australopithecus, co-existing with already existing members of the Homo genus. [15] This interpretation is based on the observation that the lower jaw, discovered by Friedemann Schrenk, of a 2.5 million year old fossil attributed to H. rudolfensis is the oldest known fossil ascribed to the genus Homo.

This specimen is thus presumed to be older than the Australopithecus sediba fossils. These critics continue to ascribe to A. africanus the status of precursor to the genus Homo. Criticism has been raised in a news report on the find in Nature , suggesting that the authors of the initial description failed to take into account the wealth of variation within A. africanus when defining the finds as an independent species. [16] Additionally, the basing of the description of the species largely on the skeleton of a juvenile specimen has been subject to criticism, given that there is no certain way of saying to what extent adults would differ from juvenile specimens. More recent reviews appear to have accepted the specific status of A. sediba as an independent species from A. africanus and other early hominins. [17] Moreover, the use of juvenile specimens as type specimens has been a common practice in palaeoanthropology: the type specimens of Homo habilis and Australopithecus africanus are themselves juvenile specimens. Australopithecus sediba fossils Original skeleton of the A.

sediba holotype MH1, on display at Maropeng, Cradle of Humankind , South Africa The pelvis of A. sediba Original courtesy of Wikipedia: — Please support Wikipedia. This page uses Creative Commons Licensed content from Wikipedia . A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. We're sorry, but there's no news about "Australopithecus sediba" right now. Limit to books that you can completely read online Include partial books (book previews) Oops, we seem to be having trouble contacting Twitter Support Wikipedia A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia! Searchlight Group Digplanet also receives support from Searchlight Group. Visit Searchlight Copyright © 2009-2016 Digparty. All rights reserved. Australopithecus sediba - Details - Encyclopedia of Life Discovery[ edit ] Matthew Berger displays the fossil he found on the Malapa Nature Reserve The first specimen of A. sediba was found by paleoanthropologist Lee Berger 's nine-year-old son, Matthew, on August 15, 2008.

[10] While exploring near his father's dig site in the dolomitic hills north of Johannesburg , on the Malapa Nature Reserve, Matthew stumbled upon a fossilized bone. [10] The boy alerted his father to the find, who could not believe what he saw — a hominid clavicle . Upon turning the block over, "sticking out of the back of the rock was a mandible with a tooth, a canine , sticking out. And I almost died", he later recalled. [10] The fossil turned out to belong to a 4 ft 2 in (1.27 m) juvenile male, whose skull was discovered in March 2009 by Berger's team. [10] The find was announced to the public on April 8, 2010. Also found at the Malapa archeological site were a variety of animal fossils, including saber-toothed cats , mongooses , and antelopes . [10] Berger and geologist Paul Dirks speculated that the animals might have fallen into a deep 100–150-foot (30–46 m) "death-trap", perhaps lured by the scent of water.

[10] The bodies may have then been swept into a pool of water with a sandy bottom and rich with lime , allowing the remains to become fossilized. [10] Age estimates[ edit ] The fossil was dated using a combination of palaeomagnetism and uranium-lead (U-Pb) dating which showed that the fossils are no older than ~2.0 Ma. The presence of animal species which became extinct at ~1.5 Ma indicates the deposit is no younger than 1.5 Ma. The sediments have a 'normal' magnetic polarity and the only major period between 2.0 and 1.5 Ma when this occurred is the Olduvai sub-Chron between 1.95 and 1.78 Ma. [5] Accordingly, the fossils were originally dated to ~1.95 Ma. Recent dating of a capping flowstone demonstrated this was not possible and the normal magnetic polarity sediments have since been correlated to the 3000-year-long Pre-Olduvai event at ~1.977 Ma. Morphology and interpretations[ edit ] A reconstruction of the skull of Australopithecus sediba. MH1.

Because of the wide range of mosaic features exhibited in both cranial and post-cranial morphology, the authors suggest that A. sediba may be a transitional species between the southern African A. africanus (the Taung Child , Mrs. Ples ) and either Homo habilis or even the later H. erectus ( Turkana boy , Java man , Peking man ). [1] The cranial capacity of MH1, which has been estimated to be at 95% of adult capacity (420 cm3), is at the higher end of the range for A. africanus and far from the lower range of early Homo (631 cm3), but the mandible and tooth size are quite gracile and similar to what one would expect to find in H. erectus; so similar are these features that, if found in isolation without other skeletal remains, they could be classified as Homo based on tooth and mandible size. However, the cusp spacing is more like Australopithecus.

Regardless of whether Australopithecus sediba is a direct ancestor of early Homo or not, our understanding of the range of variation in early hominins has been greatly increased with the finding of these new specimens. A. sediba compared to its ancestor species A. africanus on the whole is described by Berger et al. as more derived towards Homo than A. garhi , especially showing a number of synapomorphies taken to anticipate the reorganization of the pelvis in H. erectus, associated with "more energetically efficient walking and running". The femur and tibia are fragmentary, but the foot combines an advanced anklebone combined with a primitive heel. [11] Its cranial capacity is estimated at around 420–450 cm3 (26–27 cu in), [1] about one-third that of modern humans . The hand and forearm of MH2. Palmar view A. sediba had a surprisingly modern hand, whose precision grip suggests it might have been another tool-making Australopithecus. Evidence of the precision gripping and stone tool production can be seen from Homo-like features such as having a long thumb and short fingers.

[12] [13] The nearly complete wrist and hand of an adult female from Malapa, South Africa presents Australopithecus-like features, such as a strong flexor apparatus associated with arboreal locomotion . [12] A well-preserved and articulated ankle of A. sediba is mostly humanlike in form and function and possesses some evidence for a humanlike arch and Achilles tendon . However, A. sediba is apelike in possessing a more gracile calcaneal body and a more robust medial malleolus than expected. This shows that A. sediba may have practiced a unique combination of bipedalism and arboreality . [14] As opposed to the authors of the initial description, who interpreted both fossils as a possible transitional species between Australopithecus and Homo, other palaeoanthropologists are reluctant to do so. In an accompanying news article published with the initial descriptions in 2010, detractors of the idea that A. sediba might be ancestral to the genus Homo (e.g.

Tim White and Ron Clarke ) suggest that the fossils could be a late southern African branch of Australopithecus, co-existing with already existing members of the Homo genus. [15] This interpretation is based on the observation that the lower jaw, discovered by Friedemann Schrenk, of a 2.5 million year old fossil attributed to H. rudolfensis is the oldest known fossil ascribed to the genus Homo. This specimen is thus presumed to be older than the Australopithecus sediba fossils. These critics continue to ascribe to A. africanus the status of precursor to the genus Homo. Criticism has been raised in a news report on the find in Nature , suggesting that the authors of the initial description failed to take into account the wealth of variation within A. africanus when defining the finds as an independent species. [16] Additionally, the basing of the description of the species largely on the skeleton of a juvenile specimen has been subject to criticism, given that there is no certain way of saying to what extent adults would differ from juvenile specimens. More recent reviews appear to have accepted the specific status of A. sediba as an independent species from A. africanus and other early hominins.

[17] Moreover, the use of juvenile specimens as type specimens has been a common practice in palaeoanthropology: the type specimens of Homo habilis and Australopithecus africanus are themselves juvenile specimens. Australopithecus sediba fossils The original skeleton of the holotype of A. sediba, MH1, on display at Maropeng, Cradle of Humankind , South Africa. The pelvis of A. sediba. MH1 (left), Lucy (centre) and MH2 (right). Fossil remains described to date superimposed on a generalized australopithecine background. A. sediba skeletons approximately 1.3 meters tall.

Question: Australopithecus sediba, an early hominid, whose only discovered remains date to 1.78 to 1.95 million years ago, is known from two partial skeletons discovered where?
Answer: South Africa