|Fossil Man On The Path To Us|
-- Homo habilis - 1.4 Myr - 2.3 Myr
-- Homo georgicus is a new species of Homo - First in Europe - 1.7 M yr
-- Homo ergaster is an extinct chronospecies of Homo - 1.7 Myr - 2.5 Myr
-- Flat-Faced Early Humans Confirmed - Lived Among Other Human Species - 1.78 Myr and 1.95 Myr
-- Homo Rudolfensis - 1.8 Myr - 2.4 Myr
-- Australopithecus Sediba - 2 Myr
-- Homo Naledi - 2.5 Myr
-- Human ancestors spent more time in trees - 3.3 Myr
-- Home Back
My Fossil Man pages are for information about the primates that are
thought to be in the Homo Sapien Sapien line of descent. As a minimum I hope this is
Highly recommended - This place will fill your brain.
Paleontologist believe our first ancestor was the Ardipithecus ramidus followed by Australopithecus anamensis , Australopithecus afarensis ,
Australopithecus africanus , Homo rudolfensis , Homo ergaster , Homo Heidelbergensis , and finally Homo Sapiens
The Lower Paleolithic lasted from about 2.5 million-200,000 years ago (or at least according to one permutation), and it was when the, roamed most of the earth and began making the first stone tools.
Homo habilis or "Handy-man" is a species of the genus Homo, which lived from
approximately 2.3 to 1.4 million years ago at the beginning of the
Pleistocene period. Found in Tanzania, East Africa, between 1962 and
1964. Homo habilis or possibly H. rudolfensis was the earliest
known species of the genus Homo until May 2010, when H. gautengensis was
discovered, a species believed to be even older than H. habilis.
In its appearance and morphology, H. habilis is thus the least similar to
modern humans of all species in the genus (except possibly H. rudolfensis).
H. habilis was short and had disproportionately long arms compared to modern humans; however, it had a less protruding face than the australopithecines from which it is thought to have descended. H. habilis had a cranial capacity slightly less than half of the size of modern humans. Despite the ape-like morphology of the bodies, H. habilis remains are often accompanied by primitive stone tools (e.g. Olduvai Gorge, Tanzania and Lake Turkana, Kenya).
Homo habilis has often been thought to be the ancestor of the more gracile and sophisticated Homo ergaster, which in turn gave rise to the more human-appearing species, Homo erectus. Debates continue over whether H. habilis is a direct human ancestor, and whether all of the known fossils are properly attributed to the species. However, in 2007, new findings suggest that the two species coexisted and may be separate lineages from a common ancestor instead of H. erectus being descended from H. habilis.
Homo habilis is generally accepted as the supposed ancestor of the genus Homo, and often of H. ergaster most directly. This taxon's status as a legitimate species within "Homo", however, is particularly contentious. H. habilis and H. ergaster coexisted for 200,000-300,000 years, possibly indicating that these species diverged from a common ancestor. It is unclear what genetic influence H. ergaster had on later hominids. Recent genetic analysis has generally supported the Out-of-Africa hypothesis, and this may designate H. ergaster the role of ancestor to all later hominids.
georgicus: A new ancestor: It is October 10, 2002
that Europeans have officially had a new ancestor. It is based
on fossil skulls and jaws found in Dmanisi, Georgia in 1999 and a partial skeleton was discovered in 2001,
But the two skulls, a mandible and a metatarsal of 1.7 million years had
been attributed to Homo ergaster. This new species of Homo was proposed in
2002, and seems intermediate between Homo habilis and H. erectus.
The remains were first discovered in 1991 by Georgian scientist, David Lordkipanidze, accompanied by an international team which unearthed the remains. Implements and animal bones were found alongside the ancient human remains. At first, scientists thought they had found mandibles and skulls belonging to Homo ergaster, but size differences led them to name a new species.
The small skull at around 600 cm³ brain volume, the skull D2700 was first dated to 1.77 million years old and in good condition offering insights in comparison to the modern human cranial morphology. The cranium was the smallest and most primitive Hominin skull ever discovered outside of Africa. Homo georgicus is in fact 1.81 million years old. This precision is due to employee (argon39 argon40 method) dating of volcanic ash around the site. The small size of this species contrasts with the much larger size of Homo erectus. H. georgicus was the first species of Homo to settle in Europe, some 800,000 years before H. erectus.
In Africa, the Australopithecines and early Homo represent two distinctive evolutionary paths sharing a common ancestor. In Georgia the specimens, with a brain half the size of anatomically modern humans, were the smallest found until the discovery of Homo floresiensis on the island of Flores in 2003.
There is a strong sexual dimorphism present, with males being significantly larger than females. This is a primitive trait, less obvious in more modern humans in Europe (ie. Homo antecessor, Homo heidelbergensis and Homo neanderthalensis).
Later, four fossil skeletons were found, showing a species primitive in its skull and upper body but with relatively advanced spines and lower limbs, providing greater mobility. They are now thought to represent a stage soon after the transition between Australopithecus and Homo erectus. The assemblage includes one of the largest Pleistocene Homo mandibles (D2600), one of the smallest Lower Pleistocene mandibles (D211), a nearly complete sub‐adult (D2735), and a completely edentulous specimen (D3900).
Homo georgicus would lie at halfway between homo erectus, appeared in Africa 2 million years ago, and Homo erectus who left Africa for Eurasia 1.7 million years ago.
Characteristics of Homo georgicus
Skull of Homo georgicus. © dinosoria.com
The first Europeans are therefore older than believed. Fossils established that the man, originally from Africa, arrived in Eurasia 800,000 years earlier that imagined (previously was the oldest European discovered Homo antecessor of the Gran Dolina).
Reconstruction of Homo georgicus. Museum of prehistory of the Gorges of the Verdon.
Animal bones, stone tools and percussion tools have been updated with the remains of Homo georgicus. It seems that this hominid was a hunter. However, these tools are not very sophisticated. This is simple chips and "choppers" (pebbles with a face has been shaped to form a sharp edge).
Profile of Homo georgicus was established from the following fossil remains:
•1991, a mandible belonging to a young adult
•1999, skull of a young woman and a skull cap of a young man
•2000, a mandible
•2001, a complete skull and its mandible
•2005, a skull and mandible
Estimated size: 1.50 m
Peculiarity of the uncovered jaw: long, narrow and thick while ours is shorter, wider and thinner.
Brain capacity: 700 CC for the largest skull, half that of Homo sapiens. Only 600 cm3 for the smallest. Significant sexual dimorphism. Males are significantly larger than females.
Controversy over Homo georgicus The debate remains wide open regarding the allocation of the different fossils discovered. According to the authors, they belong to Homo erectus, Homo habilis, Homo erectus or Homo georgicus.
Comparison between Homo georgicus and Homo ergaster. In May 2008, Fred Spoor is expressed in French magazine search: "These fossils are simply Homo erectus." Analysis of skulls left little doubt. Some want to see Homo habilis, relying in particular on the skull of a juvenile almost adult, D2700, discovered in 2001. It's small enough, and has reconciled it KNM - ER 1813, a Homo habilis adult discovered at the Kenya, in particular stressing similarities at the level of the face.
Comparison between Homo georgicus and Homo erectus. Actually, if you look in profile, they have things in common. But if you look at other angles above for example, the resemblance is less clear. As the face is probably the last part which is taking place in an individual, and that the comparison is made between a juvenile and an adult, I'm not very impressed by these similarities.
In addition, the neurocranium D2700 strongly resembles that of Homo erectus, despite a smaller size.
Credits: first printed in dinosoria.com
Homo ergaster is an extinct chronospecies of Homo that
lived in eastern and southern Africa during the early Pleistocene, about
2.5–1.7 million years ago. There is still disagreement on the subject of
the classification, ancestry, and progeny of H. ergaster, but it is now
widely accepted to be the direct ancestor of later hominids such as Homo
heidelbergensis, Homo sapiens, and Homo neanderthalensis rather than Asian
Homo erectus. It is one of the earliest members of the genus Homo,
possibly descended from, or sharing a common ancestor with, Homo habilis.
Many paleoanthropologist still debate the definition of H. ergaster and H. erectus as separate species. Some call H. ergaster the direct African ancestor of H. erectus, proposing that H. ergaster emigrated out of Africa and into Asia, branching into a distinct species. Most dispense with the species-name ergaster, making no distinction between such fossils as the Turkana Boy and Peking Man. Though "Homo ergaster" has gained some acceptance as a valid taxon, H. ergaster and H. erectus are still usually defined as distinct African and Asian populations of the larger species H. erectus. (For the remainder of this article, the name "Homo ergaster" will be used to describe a distinct species for the convenience of continuity in reading.)
H. ergaster may be distinguished from H. erectus by its thinner skull-bones and lack of an obvious supraorbital foramen. It may be distinguished from Homo heidelbergensis by its thinner bones, more protrusive face, and lower forehead. Derived features separating it from earlier species include reduced sexual dimorphism, a smaller, more orthognathous (less protrusive) face, a smaller dental arcade, and a larger cranial capacity (700-900cm³ in earlier ergaster-specimens, and 900-1100 in later specimens). It is estimated that male H. ergaster stood 1.89 meters (6 ft 2 in) tall. Remains have been found in Tanzania, Ethiopia, Kenya, and South Africa.
Homo ergaster was probably the first hominid to "use a human voice", though its symbolic cognition was probably somewhat limited compared to modern humans.
H. ergaster is believed to have diverged from the lineage of H. habilis between 1.9 and 1.8 million years ago; the lineage that emigrated Africa and fathered H. erectus diverged from the lineage of H. ergaster almost immediately after this. These early descendants of H. ergaster may have been discovered in Dmanisi, Georgia. H. ergaster remained stable for ca. 500,000 years in Africa before disappearing from the fossil record around 1.4 million years ago. No identifiable cause has been attributed to this disappearance; the later evolution of the similar H. heidelbergensis in Africa may indicate that this is simply a hole in the record, or that some intermediate species has not yet been discovered.
Homo ergaster used more diverse and sophisticated stone tools than its predecessor, Homo habilis. H. ergaster refined the inherited Oldowan developing the first Acheulean bifacial axes: while the use of Acheulean tools began ca. 1.6 million years ago, the line of H. erectus diverged some 200,000 years before the general innovation of Acheulean technology. Thus the Asian migratory descendants of H. ergaster made no use of any Acheulean technology.
Flat-Faced Early Humans Confirmed—Lived Among Other Human Species
Until now, the fossil species—still nameless—"has always been an enigma.".
A new fossil jaw is among evidence for a new human species.
Updated August 8, 2012 James Owen for National Geographic News
New fossils recast a flat-faced oddity as a star species in the first chapter of the human story—perhaps even as our oldest known truly human ancestor.
At the least, the fossils confirm that at least three different human species inhabited the same Kenyan neighborhood at the dawn of humanity, according to a new study led by paleontologists Meave and Louise Leakey.
(Related: "Human Ancestor May Put Twist in Origin Story, New Studies Say.")
Consisting of a face, a complete lower jaw, and part of a second jaw, the new fossils were found east of Kenya's Lake Turkana between 2007 and 2009. The products of a 40-year search, they provide the needed evidence to confirm that a disputed skull found in 1972 does in fact represent a new species, the team says.
Dated to between 1.78 million and 1.95 million years ago, the remains were uncovered within six miles (ten kilometers) of the 1972 skull, which was discovered by Meave Leakey's husband, paleoanthropologist Richard Leakey.
Known as KNM-ER 1470—"1470" for short—the skull has "always been an enigma," said Meave, of the Koobi Fora Research Project. "We've never known exactly what it was and how it fitted in with anything else." Now, finally, "we know that flat face is real—it isn't just an aberrant specimen," said Meave, a National Geographic Society explorer-in-residence.
Not an aberrant specimen, but a different species from the early Homo varieties previously known to have inhabited Turkana: Homo habilis ("handy man"), the presumed tool user conventionally seen as the earliest known Homo species, and Homo erectus, the "upright man" believed to be a direct ancestor of our own species.
"With these new fossils," Meave said, "we can definitely say there are two groups of non-erectus" living side-by-side at Lake Turkana. "As opposed to other species of Homo, which had rather protruding faces, what would have struck you was how flat and broad the face was," Meave said of 1470. "The brain case is beginning to get a little bit of a forehead, because it's quite a big brain in there, but nothing like the brain of Homo erectus," which likely arose later, she added.
For now the study team is avoiding the previously proposed name for the flat-faced species, H. rudolfensis, because the relationships between the fossil specimens and the species names remains uncertain. Further research may show that a key H. habilis fossil should be grouped in the same species as 1470, in which case 1470 would itself be classified as H. habilis, and some smaller, more primitive-looking fossils currently called H. habilis would be given another name
While this creates a bit of an academic headache, it doesn't affect the fact that "the new finds allow us to reclassify the whole collection of non-erectus fossils into two groups which have clear defining statistics," the Leakeys' team writes in a statement.
Physical anthropologist William Kimbel agrees. The latest fossils "go a long way to easing concerns about whether 1470 could be a one-off—just an odd variant of Homo habilis, for example," said Kimbel, director of the Institute of Human Origins at Arizona State University, who wasn't part of the study team.
Our Oldest Homo Ancestor?
If we now have two Homo species at the base of the human tree, which of them gave rise to Homo erectus, our direct ancestor? Kimbel thinks the anatomy of H. habilis—which had a smaller, more protruding face than 1470—makes it a more likely ancestor for H. erectus. "But," he added, "I've heard arguments to the contrary."
Bernard Wood, professor of human origins at the George Washington University, noted that 1470 probably had a larger brain than H. habilis, "but that doesn't necessarily make  an ancestor for Homo erectus."
"Some of the smaller Homo erectus crania have remarkably small brains," suggesting that H. erectus' big brain may have developed within the species, as opposed to being inherited from an ancestral species.
Because the new species is known from only skull fragments, Wood likens the puzzle to "trying to work out the relationship between three motor cars when all you've got are bits of the gear box."
Another question is how the three early humans co-existed without stepping on each other's toes.
"Given the fact that they were all terrestrial bipeds of one sort or another," differences in how the three species made a living—and where they chose to live—would have come down to diet, as opposed to, say, climbing ability, Arizona State's Kimbel said.
One possible clue emerging from the study is that 1470 and its kind were powerful chewers.
"The cheekbones are so far forward it means they would have been able to use quite a strong biting force," Meave Leakey said.
With a chewing advantage, 1470 may have gravitated toward areas rich with nuts or tough fruits, or perhaps even meat, leaving the softer stuff to erectus and habilis. (Related: "Lucy the Butcher? Tool Use Pushed Back 800,000 Years.")
It could also be that these early human species just plain got along.
"Modern primates are generally very good at living together," Leakey said. "You can see troops of monkeys composed of at least two species, if not more."
One thing's for sure: Untangling our roots at Turkana isn't going to be easy, George Washington University's Wood said.
"Darwin said it was going to be very difficult to locate the origin of Homo," Wood said. "I think, as usual with Darwin, he was right on the money."
Corrected: Original version incorrectly said the new species as a whole was tentativey being called 1470, after the fossil specimen identified by that number.
Homo Rudolfensis [This example is from
http://archaeologyinfo.com/homo-rudolfensis/ I am surprised
that for the first time an artist rendition of fossil man is shown without a
ton of hair that seems to dominate most all other renditions.
There is currently an on going debate about at what time most all body hair
disappeared - that debate is more in-depth in the DNA community, some
believe they have discovered the "hair" gene, obviously there is much more
research needed. But also recient documentaries by the BBC
depict our ancestors, as hairless as we are today, although you
might know of some that seem to have gene regression. I have
read that humans actually have more hail than a gorilla but because it is so
light you can't see it. But, regarding color, it seems everyone
expects all people of African origin to be black, I have yet to hear
that skin has ever been discovered on a fossil. We do know the
Sahara has been a place of much rain, forest, fruits and game in abundance.
Even today not all people of Africa are black. Someday, DNA may
be able to answer that question. The bush men of Africa for
instance may be the oldest Homo sapiens living and they are brown.]
This species designation of Homo rudolfensis is a much debated topic, over both whether it is a separate species, and if it is an australopithecine rather than a member of the genus Homo. The type specimen of the species is KNM-ER 1470 and was discovered by Bernard Ngeneo of Richard Leakey’s team in 1972, east of Lake Turkana at Koobi Fora in northern Kenya. This discovery was of a fairly complete cranium without any remaining teeth. Due to uncertainties created by its large brain size and its early initial dates, Leakey did not attribute the specimen to a species, but simply as a member of the genus Homo.
Richard Leakey's research team attributed the toothless cranium to the genus Homo with the species indeterminate due to the large brain size and questionable morphological association with known hominids. The cranium was reconstructed by Meave Leakey into two main pieces that give an estimated brain size of 775cc. The specimen was originally thought to be around 2.9 myr old, due to an inaccurate dating of 2.6 myr for the KBS volcanic tuff located above it. This inaccuracy was caused by contamination of older material, and the tuff is now know to be much younger. The specimen is now thought to date to approximately 1.8 myr. Though this date is now generally accepted for the specimen, the geologists who originally dated the KBS tuff continue to argue for a later date for the specimen. While they admit the dating of the volcanic tuff was inaccurate, F. Fitch and colleagues claim that the depth of the specimen beneath the tuff shows a much earlier age, dating to around 2.4 myr.
| Australopithecus Sediba Two-million-year-old fossils—and possibly
Published September 8, 2011 Ker Than for National Geographic News
Human Ancestor May Put Twist in Origin Story, New Studies Say. The skull of the young male Australopithecus sediba rests near the spot in Africa where he died.
Photograph by Brent Stirton, National Geographic
Two-million-year-old bones—and possibly skin—from a pair of primate fossils are offering new insight into the apelike species that may have given rise to the first humans. Known as Australopithecus sediba, the ancient human ancestor was discovered in the Malapa region of South Africa in 2008 and was described for the first time last April.
Now a suite of five studies, published in this week's issue of the journal Science, is delving deeper into the species' unusual mix of human and apelike traits to help refine A. sediba's place in the time line of human evolution.
After examining A. sediba's anatomy, for instance, scientists think they may have evidence that the species was capable of making and using tools.
In addition, the team thinks it may have found samples of fossilized skin. If confirmed, the discovery would mark the first time any type of soft tissue has been recovered from an early human ancestor. "We've started an open-access experiment"—called the Malapa Soft Tissue Project—"to determine if we do in fact have skin," said study leader Lee Berger, an anthropologist at the University of the Witwatersrand in Johannesburg. "We are enlisting the entire scientific community in exploring this possibility."
Overall, Scott Simpson, a paleontologist at Case Western Reserve University in Cleveland, Ohio, called the fossils "extraordinary."
"They come from a time period that is very important, circa two million years ago, that we just don't know a lot about," said Simpson, who did not participate in the studies.
Fossils Show Evolutionary Tinkering
The A. sediba skeletons belong to a male child in his early teens and a female thought to be roughly 30 years old. The pair likely died within days or perhaps even hours of each other and may have been related.
The two primates apparently fell into a chasm, coming to rest in an underground cave system also littered with the bones of other animals. Over time this ancient "death trap" filled with breccia, a cemented stone material that helped preserve the remains.
The new studies build on previous work showing that A. sediba possessed an unusual mix of primitive and derived—or humanlike—traits.
For example, the partial pelvis and right foot of the adult female suggest that A. sediba was capable of standing and walking upright. Its ankles were very humanlike, but it had thin, apelike heels.
This odd combination of foot features suggests the 4-foot-tall (1.2-meter-tall) A. sediba almost certainly still climbed trees, the team says, yet was also capable of walking upright on the ground, much like a human.
"I don't think any of us ever imagined that this particular suite of anatomy would exist in the human fossil record," Brian Richmond, a paleoanthropologist at George Washington University who was not involved in the study, said of the A. sediba fossils in general.
"But it actually fits perfectly with the way evolution tinkers and plays with anatomy, so it's exciting to see these evolutionary experiments and processes happening in our own family tree."
Human Ancestor Had "Precision Grip"
Also surprising are A. sediba's hands and brain, which, when considered together, raise the possibility that the creature had the capacity to create and use stone tools.
Using powerful x-ray scans, the team created a virtual mold, or endocast, of the braincase of the A. sediba child.
"With every heartbeat, the brain pounds out its shape on the developing skull of a child, eventually leaving a beautiful impression of the external shape and form of the brain on the inside of the skull," study co-author Kristian Carlson, also from the University of Witwatersrand, explained in a statement.
"By mapping the contours of this surface, a clear image of the original brain located in the skull can be produced."
The endocast shows that the overall shape and organization of A. sediba's brain was similar to that of modern humans yet was surprisingly small—only about a quarter the size of a modern human brain, or a little larger than the brain of a chimpanzee.
"What this study is showing reinforces the idea that our brains began reorganizing [into a more humanlike configuration] before there was any dramatic change in size," George Washington University's Richmond said.
A. sediba's possible abilities as a toolmaker are also supported by an analysis of the right hand of the female skeleton, which is the most complete hand yet known from an early hominin—the term that refers to our ancestors and their close evolutionary relatives.
The hands of most early hominins are known from just a few isolated bones gathered from different individuals and cobbled together. But in the case of the A. sediba female, only a few hand bones—the tips of four fingers and a wrist bone—are missing.
The fossil hand shows A. sediba had a relatively long thumb compared with its other fingers. This would have given the species a remarkably humanlike "precision grip," which is necessary for making stone tools.
A precision grip is one that involves the thumb and fingers but not the palm. Other primates are capable of some precision grips, but humans are unique in their ability to apply force with these grips and use them for fine manipulations.
According to the study authors, A. sediba would have an excellent precision grip. In fact, its hands might have been even more agile than ours, because of its longer thumb.
"It was kind of hyper-human in that regard," Richmond said.
New Fossils Reshaping Family Tree?
Oddly, A. sediba's grip appears to have been more humanlike than that of the larger-brained and bigger-bodied Homo habilis, which is widely considered to be the earliest known member of the genus Homo.
However, the A. sediba fossils are about 300,000 years younger than an upper jaw, discovered by anthropologist William Kimbel, that's thought to belong to a species of Homo, possibly H. habilis.
Still, Berger and his team think it's possible A. sediba gave rise to the Homo genus. (Explore a graphic of the possible branches on the human family tree.) The researchers suggest the Malapa specimens could have been younger remnants of an enduring species that gave rise to Homo at an earlier date.
Alternatively, H. habilis may have represented a failed side branch of the human family tree, and it was actually A. sediba that was the direct ancestor of Homo erectus, the species widely regarded as the immediate forerunner of modern humans, Homo sapiens.
"We're saying you have to at least consider that possibility," Berger said.
A. Sediba Posing Tough Questions
But George Washington University's Richmond said he is not ready to accept such a drastic revision to the human time line.
"The craniodental evidence that H. habilis is the ancestor of H. erectus is still too compelling to force H. habilis out as a side branch," he said. "I don't think the data supports that view yet."
Anthropologist Philip Rightmire of Harvard University is also hesitant to make such a leap, for the same reason.
"The origins of H. erectus are still quite mysterious at this point," said Rightmire, who was not part of the study.
"We just don't know what happened. But I think that H. habilis is still the best bet. If you want to put your money on one horse or the other, that would be the one."
Case Western's Simpson added that these and other tough questions about human evolution are what make the A. sediba fossils so important.
"Good fossils allow you to fill in things you already suspect and support existing ideas, but great fossils are completely unexpected," he said.
"These are fossils that have to be dealt with, and that's not a bad thing at all."
|Australopithecus sediba hominin: New study reveals how
human ancestor walked, chewed, and moved
April 11, 2013 Extract from PHYS-ORG
Composite reconstruction of Au. sediba based on recovered material from MH1, MH2 and MH4 and based upon the research presented in the accompanying manuscripts. As all individuals recovered to date are approximately the same size, size correction was not necessary. Femoral length was established by digitally measuring a complete femur of MH1 still encased in rock. For comparison, small-bodied female modern H. sapiens on left, Male Pan troglodytes on right. Credit: Lee Berger, University of the Witwatersrand
A team of scientists has pieced together how the hominid Australopithecus sediba (Au. sediba) walked, chewed, and moved nearly two million years ago. Their research, which appears in six papers in the latest issue of the journal Science, also shows that Au. sediba had a notable feature that differed from that of modern humans—a functionally longer and more flexible lower back.
Together, the studies offer a comprehensive depiction of some of the most complete early human ancestral remains ever discovered.
Since its discovery in August 2008, the site of Malapa—located about 30 miles northwest of Johannesburg—has yielded more than 220 bones of early hominins representing more than five individuals, including the remains of babies, juveniles, and adults. The evidence published in Science is based on two individuals from the site. The fossils from the site date to 1.977 to 1.98 million years in age.
"The abundance and remarkable preservation of fossils from Malapa provide unique insights into the way this fascinating extinct species interacted with and moved around in its environment," said New York University anthropologist Scott Williams, the lead author of one of the six papers appearing in Science.
Williams, part of NYU's Center for the Study of Human Origins, and his colleagues authored a paper describing Au. sediba's vertebral column. The work is the first to analyze elements of the cervical, thoracic, lumbar, and sacral regions of the vertebral column in Au. sediba. Their analysis was based on partially complete spines of the two Au. sediba skeletons.
Their study reveals that Au. sediba had a human-like curvature of the lower back, but it was functionally longer and more flexible than that of modern humans.
"They probably walked in a way that we might find strange—a 'compromise' form of bipedalism indicative of a hominin that still partially relied on climbing trees," Williams explained.
He noted that "the adult female is the first early hominin skeleton that preserves an intact terminal thoracic region and this provides critical information on the transition in inter-vertebral joints, and, by inference, mobility of the lower back."
"The bony spine of Au. sediba likely had the same number of vertebrae as that of modern humans," Williams added. "However, it differed in one primary aspect of its configuration—the transition in inter-vertebral articular facets occurred at a higher level of the spine that than normally occurs in modern humans. In combination with other features, a functionally longer lower back would have allowed for a more flexible spine in Au. sediba relative to that of modern humans."
In addition, morphological indicators of strong lumbar curvature suggest that Au. sediba evolved in this regard relative to Au. africanus, which lived between 3.03 and 2.04 million years ago, and closer to the more recent Nariokotome Homo erectus skeleton—to date, the most complete early human skeleton discovered.
The research was conducted at the Evolutionary Studies Institute (ESI) at the University of the Witwatersrand (Wits) in South Africa, where Au. sebida's remains were discovered in 2008.
Overall, the fossils provide an "unprecedented insight into the anatomy and phylogenetic position of an early human ancestor," observed Professor Lee Berger, the project leader from the Wits Evolutionary Studies Institute. "This examination of a large number of associated, often complete and undistorted elements, gives us a glimpse of a hominin species that appears to be mosaic in its anatomy and that presents a suite of functional complexes that are both different from that predicted for other australopiths, as well as that for early Homo.
"Such clear insight into the anatomy of an early hominin species will clearly have implications for interpreting the evolutionary processes that affected the mode and tempo of hominin evolution and the interpretation of the anatomy of less well preserved species."
AU. SEDIBA FACT SHEET ON SIX PAPERS
INTRODUCTION: MOSAIC ANATOMY OF AUSTRALOPETHICUS SEDIBA
Prof. Lee Berger, researcher in the Wits Evolutionary Studies Institute (ESI) at the University of the Witwatersrand, project leader and lead author of the introduction entitled Mosaic Anatomy of Australopethicus Sediba, summarises that Au. sediba provides the most comprehensive examination of the anatomy of a definitive single species of early hominin.
"This examination of a large number of associated, often complete and undistorted elements, gives us a glimpse of a hominin species that appears to be mosaic in its anatomy and that presents a suite of functional complexes that are both different from that predicted for other australopiths, as well as that for early Homo," says Berger.
"Such clear insight into the anatomy of an early hominin species will clearly have implications for interpreting the evolutionary processes that affected the mode and tempo of hominin evolution and the interpretation of the anatomy of less well preserved species."
DENTAL MORPHOLOHY AND THE PHYLOGENETIC "PLACE" OF AUSTRALOPETHICUS SEDIBA
The first paper, by lead author Prof. Joel Irish from the Research Centre for Evolutionary Anthropology and Palaeoecology at Liverpool John Moores University in the United Kingdom and his co-authors, examines non-metric dental traits in Au. sediba.
The study concludes that the species is distinct from east African australopiths, but is close to Au. africanus, thus forming a southern African australopith clade.
The latter, in turn, shares a number of derived states with a clade comprising four fossil samples of the genus Homo. This surprising result has significant implications for our present understanding of hominin phylogeny through the terminal Pliocene, and alludes to the possibility that Au. sediba, and perhaps Au. africanus are not descendant from the Au. afarensis lineage.
Irish noted that even though the results of this study were surprising and were bound to be viewed as controversial given the long held hypotheses relating to the origins of the genus Homo he would have come to the same conclusion.
"The extreme age and rarity of these fossils naturally draws enhanced interest in and scrutiny of any new findings. Based on the evidence, I would have come up with the same conclusions whether the samples were three million or 30 years old. If I had found that Au. sediba was totally distinct from all other hominins, I would have been just has happy to report that," says Irish.
MANIDBULAR REMAINS SUPPORT TAXONOMIC VALIDITY OF AUSTRALOPETHICUS SEDIBA
Prof. Darryl de Ruiter from the Department of Anthropology, Texas A&M and the Evolutionary Studies Institute at the University of the Witwatersrand, and his co-authors examine new mandibular material attributable to MH2, including the previously unknown mandibular incisors and premolars of Au. sediba held in a spectacular new mandibular specimen associated with the female paratype specimen.
The study concludes, as is seen elsewhere in the cranium and skeleton, these mandibular remains share similarities with other australopiths, but can be differentiated from the southern African ape-man Au. africanus in both size and shape, as well as in their unique ontogenetic growth trajectory.
"These results add further support to the claim that Au. sediba is taxonomically distinct from the temporally – and geographically – close species Au. africanus. Where the Au. sediba mandibles differ from those of Au. africanus, they appear most similar to representatives of early Homo," says De Ruiter.
He adds that "everywhere we look in these skeletons, from the jaws on down to the feet, we see evidence of the transition from australopith to Homo; everywhere we see evidence of evolution."
THE UPPER LIMB OF AUSTRALOPETHICUS SEDIBA
In the third paper by Prof. Steven Churchill from the Department of Evolutionary Anthropology at Duke University and the Evolutionary Studies Institute at University of the Witwatersrand, he and his co-authors describe new, remarkably well preserved upper limb elements of Au. sediba.
The paper announces the first complete (or nearly complete) and undistorted humerus, radius, ulna, scapula, clavicle and manubrium (a frontal chest bone) yet described from the early hominin record, all associated with one individual.
The authors note that with the exception of the hand skeleton (which exhibits a suite of derived features that may signal enhanced manipulative capabilities relative to earlier australopiths), the upper limbs of the Malapa hominins are largely primitive in their morphology. Au. sediba thus shares with other australopiths an upper limb that was well-suited for arboreal or other forms of climbing and possibly suspension, though perhaps more so than has been previously suggested for any other member of this genus.
Churchill adds that "it is possible that the climbing features in the skeleton of Australopithecus sediba and other australopiths are functionally unimportant primitive traits retained from a more arboreal ancestor. Even so, it is curious that these features persist unchanged for several million years, only to abruptly disappear with the emergence of the genus Homo."
MOSAIC MORPHOLOGY IN THE THORAX OF AUSTRALOPETHICUS SEDIBA
Remains of the rib cage of Au. sediba are described in the fourth paper by Dr Peter Schmid and his co-authors at the Evolutionary Studies Institute at the University of the Witwatersrand and the University of Zurich.
Their findings reveal a mediolaterally-narrow upper thorax like that of the large-bodied apes, and unlike the broad, cylindrical chest seen in humans. In conjunction with the largely complete remains of the shoulder girdle, Schmid notes that "the morphological picture that emerges is one of a conical thorax with a high shoulder joint that produces in Au. sediba an ape-like "shrugged" shoulder appearance, and thus a configuration that is perhaps uniquely australopith, and that would not have been conducive to human-like swinging of the arms during bipedal striding and running".
The research however shows that the less well-preserved elements of the lower rib cage suggest a degree of human-like, mediolateral narrowing to the lower thorax. This indicates a surprising and rather unsuspected mosaic anatomy in the chest that is not like that observed in H. erectus or H. sapiens.
THE VERTEBRAL COLUMN OF AUSTRALOPETHICUS SEDIBA
Dr Scott Williams from the Center for the Study of Human Origins, Department of Anthropology, New York University and co-authors on the fifth paper describing the vertebral column of Au. sediba is the first paper to analyse elements of the cervical, thoracic, lumbar, and sacral regions of the vertebral column in Au. sediba.
Among the material described is a remarkably articulated lumbar vertebral region that shows a human-like curvature of the lower back. Williams notes that "the adult female is the first early hominin skeleton that preserves an intact terminal thoracic region and this provides critical information on the transition in inter-vertebral joints, and, by inference, mobility of the lower back".
The study also demonstrates that Au. sediba had the same number of lumbar vertebrae as modern humans, but possessed a functionally longer and more flexible lower back. In addition, morphological indicators of strong lumbar curvature suggest that Au. sediba was derived in this regard relative to Au. africanus and more similar to the Nariokotome Homo erectus skeleton.
THE LOWER LIMB AND THE MECHANICS OF WALKING IN AUSTRALOPETHICUS SEDIBA
The sixth paper by Dr Jeremy DeSilva and his co-authors at Boston University and the Evolutionary Studies Institute at the University of the Witwatersrand describes the lower limb anatomy of Au. sediba is described and a specific biomechanical hypothesis is proposed as to how this species walked.
"The female Australopithecus sediba preserves a heel, ankle, knee, hip and lower back- all of the ingredients necessary to reconstruct how she walked with remarkable precision. Even the famous Lucy skeleton only preserves two of these five (ankle and hip)", says DeSilva.
In isolation, the anatomies of the heel, mid-foot, knee, hip, and back are unique and curious, but in combination, they are internally consistent for a biped walking with a hyper-pronating gait.
"The implications of this study are that multiple forms of bi-pedalism were once practiced by our early hominin ancestors," adds Berger.
More information: "The Mosaic Nature of Australopithecus sediba," by L.R. Berger, Science, 2013.
"Dental Morphology and the Phylogenetic 'Place' of Australopithecus sediba," by J.D. Irish , Science, 2013.
"Mandibular Remains Support Taxonomic Validity of Australopithecus sediba," by D.J. de Ruiter, Science, 2013.
"The Upper Limb of Australopithecus sediba," by S.E. Churchill, Science, 2013.
"Mosaic Morphology in the Thorax of Australopithecus sediba," by P. Schmid, Science, 2013.
"The Vertebral Column of Australopithecus sediba," by S.A. Williams, Science, 2013.
"The Lower Limb and Mechanics of Walking in Australopithecus sediba," by J.M. DeSilva, Science, 2013.
A New Human
Relative, Homo Naledi
December 07, 2015 By DANIEL WEISS Johannesburg, South Africa
(Courtesy John Hawks/Wits University)
A composite skeleton and an array of other bones belonging to multiple members of a previously unknown hominin speciesScientists have long searched for the transitional species between apelike australopithecines, such as Lucy (Australopithecus afarensis), and early humans, such as Homo habilis. And now, deep in the Rising Star cave system in South Africa, they may have unearthed it.
When amateur cavers told Lee Berger, a paleoanthropologist at the University of the Witwatersrand in Johannesburg, that they had located hominin remains in the nearby cave system, he knew he could not make it in to retrieve them himself. The passageway was extremely narrow, just seven inches wide at one point. So Berger put out a call on Facebook for diminutive, non-claustrophobic scientists and recruited a team of six women who fit the criteria.
Marina Elliott, an archaeologist from Simon Fraser University in Canada, was the first to enter the chamber. “I was stunned,” she says. “I shone my headlight around and picked up flashes of bone all over the place.” Elliott and her colleagues retrieved more than 1,500 specimens, from at least fifteen different individuals. A larger team of scientists, led by Berger, determined that the remains belong to a previously unknown species, which they named Homo naledi after its resting place—naledi means “star” in the local Sesotho language.
Homo Naledi Skull
(Courtesy Wits University)
Skull of Homo nalediThe newly discovered species had a novel mix of primitive and modern features. Its head was tiny, with a brain the size of an orange, but its skull was humanlike in shape. Its hands were adapted for manipulating objects and its feet for walking upright, but its shoulders and fingers were built for climbing. “We never expected to see a combination of characteristics like this,” says John Hawks, a paleoanthropologist at the University of Wisconsin–Madison, “but they’re all in Homo naledi, and that’s surprising.”
The researchers suspect Homo naledi may be among the earliest members of the genus Homo, which would mean it most likely existed around 2.5 million years ago. However, they have so far been unable to date the remains.
Human ancestors spent more time in trees: Study
Oct 27, 2012 (IANS)
Our early human ancestors spent much of their time in trees long after they fully mastered the art of walking on two legs, according to a study.
This came to light after the remains of a three-year-old girl who died about 3.3 million years ago in East Africa were found.
The discovery appears to have ended the debate over whether this bipedal hominid still continued to climb trees, much like their earlier ape ancestors, The Independent reported Friday.
The fossilised shoulder blades and arm sockets belonging to Selam, meaning "peace", indicate that she and her family continued to climb trees like modern apes even though her lower body was perfectly adapted to upright walking.
This means that humanity's earliest ancestors abandoned an arboreal existence far later in our evolutionary history than previously thought, the newspaper said.
Selam is a remarkably well-preserved specimen of the species Australopithecus afarensis, an important forerunner of the human lineage.
Her almost-complete skull and skeleton, embedded in sandstone rock, was discovered in 2000 in Dikika region of Ethiopia.
And it has taken years of painstaking work for scientists at the California Academy of Scientists to extract the fossilised bones from the stone, the daily said.
I was once ask if I was promoting pornography by having this image on my web
– the answer is no. This and other “nude” images are from reputable
paleontologist illustrators, and all are the best guess about our
progenitors. It is thought the vast numbers of primates of the family
Hominidae that eventually led to Homo sapiens developed in the very hot
climates in Africa, therefore the “nude” attire. For instance, you don’t see
apes in the wild wearing body cover today; it is therefore natural to
illustrate them as “nude”. The female is shown with enlarge breast because,
the though is that this group’s DNA has modified away from their primate
ancestors and are indicative of the beginning of the homo sapiens or human
side of the hominid species. Our species have small canines and some think
the females chose to reproduce with males with smaller canines. So can we
say it was a trade off, males with small canines and females with enlarged
breast, better adapted to survival of the babies, therefore the species.
Wildlife film shows a leopard will often run from a large baboon with their huge canines, so now how is the male to protect the females and kids, now he is forced to invent fighting tools, and look where that has led.
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