Q and A and answers to Frequently Asked Questions about Australopithecus sediba What does Australopithecus sediba mean? Australopithecus means “southern ape”, after the genus of the Taung child, named by Raymond Dart “sediba” means “natural spring”, “fountain” or “wellspring”  in Sotho. Why did you choose the name sediba? The name seemed appropriate for a species that might be the point from which the genus Homo arises. Where was it discovered? At the Malapa site in the Cradle of Humankind World Heritage site.  We are trying to keep the exact location confidential. What does Malapa mean? Malapa means “my home or homestead” in Sotho. What is a hominid/hominin? A hominid is a member of the taxonomic family that includes humans, chimpanzees, gorillas, and their extinct ancestors.  Hominins are members of the human branch (after the human lineage split from that of chimpanzees) , and thus include living humans and extinct human ancestors(such as the Australopiths)  Hominins are characterized by bipedal locomotion (although this may not have been the case for the very earliest members of the group) and relatively  small canine teeth.  Later members of this group (those in our genus, Homo) are characterized by  larger brains than those of living apes ( chimpanzees, bonobos, gorillas, orang-utans and gibbons).  A good description of the difference between a hominid and hominin may be found at: http://news.nationalgeographic.com/news/2001/12/1204_hominin_id.html When was it/they discovered? The site was discovered by Lee Berger on August the 1st 2008.  The first skeleton (the juvenile male) was discovered on the 15th of August 2008 by 9 year old Matthew Berger when he found its clavicle embedded in a block of rock.  The second skeleton was found on the 4th of September 2008 by Lee Berger. How old are the fossils? 1.78 to 1.95 million years. They were dated by a variety of methods including Uranium-Lead, Palaeomagnetics and faunal dates.   Cosmogenic dating was used to interperet the landscape formation and how deep the cave was at the time The fossils are preserved in a cave? The site where the fossils were discovered is technically the infill of a de-roofed cave that was as much as 50 meters underground 1.9 million years ago.  They appear to have fallen, along with other animals, into a deep cave, landing up on the floor for a few days or weeks. The bodies were then washed into an underground lake or pool probably pushed there by a large rainstorm.  They did not travel far, maybe a few meters/yards where they were solidified, as if thrown into quick setting concrete.  The rock they are preserved in is called a calcified clastic sediment – not a breccia. Over the past 1.9 million years the land has eroded down to expose the fossil bearing sediments. Why were they in the cave? How did they die? The skeletons were found with other animals in similar states of preservation (many of them in partial articulation).  There are antelopes, carnivores, even mice and hares.   We are hypothesizing that all of these animals died accidental deaths, either by stumbling into the vertical cave shaft that was hidden by vegetation, or perhaps falling in while trying to reach the water at the bottom of the cave.   There is as of yet no evidence of scavenging by carnivores but there is some insect damage. Did they die at the same time, was it a catastrophe? The hominin skeletons were found with the bones either in partial articulation or in close anatomical association, which suggests that both bodies were only partially decomposed at the time of deposition in the lower chamber.  This further suggests that they died very close in time to each other, either at the same time, or hours, days or weeks apart, but probably not much longer than that. Were they related to each other? Since they lived at the same time and in the same place, and if they behaved like modern primates then they were most probably part of the same troop and were probably related to each other. Was this a mother and child? Its possible, we’re doing everything possible to determine if this is the case.  Regardless, they were probably related to each other in some way. What is the area like?   The bedrock of the area is a dolomitic limestone, dated to around 2.5 billion years.  The site is in a protected wilderness area in the Cradle of Humankind World Heritage site. How old is the child? The Type specimen is a male child, around 10 – 13 years old in human developmental terms.  It was probably  a bit younger in actual age (perhaps as young as eight or nine or so) as they most likely   matured faster than us. The age estimate is based on modern human standards by which we evaluate the eruption stages of the teeth and  thedegree of development of the  growth centres of the bones.   Determining the actual age at death (and thus how much more quickly Au. sediba grew than do modern humans) will require microscopic examination of dental enamel,  which we plan to do in the near future. How old is the female skeleton? We don’t know exactly but based on the extreme wear of her teeth, she is probably at least in her late twenties or early thirties, maybe a bit older. Had she had children? We cannot say for certain, but it is most likely that a female Australopith of her age would have had children. We may be able to tell with further finds.How do you know the child is a male? There are features of the face that help us determine that the child is a male.   The muscles of the child are larger than that of the other skeleton, even though it is a child.  There are also features of the pelvis that we can use to determine that it is a male. How tall were they? We estimate that they were both about 4’ 2” (1.27 meters) tall. This is comparable to estimates (from Henry McHenry) for adults of Au. africanus (males average 1.38m, females average 1.15m).  The child would certainly grow taller. How big were they? When equations appropriate for estimating mass in small-bodied humans are used, we estimate that the female had a mass of about 33 kg (ca. 73 lbs), while the juvenile was about 27 kg (ca. 59 lbs)at the time of death (but would have grown to be larger).  When the same methods are applied to specimens of Au. africanus, male specimens produce a mean mass of 41 kg, while females average about 30 kg. How big is their brain? Around 420 – 450 cubic centimetres, which is small, but the shape of the brain is more advanced than you would find in australopithecines.  It has wide temporal lines (a good illustration of this is to put your fingers on the side of your head to show them the line of the chewing muscles while they move their mouth – for the non-anatomists, the temporal muscles move your jaw up and down).  For comparative purposes human brains are about 1200 to 1600 cubic centimetres; Homo habilis has about 600 cubic centimetres; Australopithecus africanus about 400 to 525 cubic centimetres; Homo floresiensis about 350 cc’s; a chimpanzee about 350 cc’s. What did they look like? They had a small brain, a somewhat pronounced nose, long arms like an orang-utan but short powerful hands like a human.  The pelvis and hip are advanced, similar to modern humans and Homo erectus.   Their legs appear long and their ankles seem to be intermediate between ours and earlier hominids. Could they run? Almost certainly maybe not exactly like we can but moreso than other earlier hominids which had shorter legs and more primitive pelvises and hip joints. Did they climb? Almost certainly.  They had long powerful arms that were probably used for climbing. We had suspected other early hominids had long arms like this, Homo habilis, Au. Africanus and lucy but we had never found a complete arm before so the actual length was a bit of a surprise. How does this relate to Lucy? Australopithecus sediba is  around a million years younger than Lucy. Some scientists feel that Lucy’s species, Au. Afarensis, gave rise to Au. africanus and we are suggesting Au. africanus or something similar, gave  rise to Au. Sediba. What do you call them?  Their popular names?   The female will have a common name, we’ll give you the meaning.  The child is being named in a national competition where children will choose a name for it.  It was eventually named "Karabo" which means - the answer. What was their world  like? That is one of the things we are working on right now.  We will use plants and animals found with the fossils to determine, probably extremely accurately but it was almost certainly more forested than the area today. We are undertaking studies of their teeth and other aspects of the site to establish exactly what their diet and lifestyle was. Why isn’t this the genus Homo? The specimens have an overall body plan that is like that of other Australopiths: small brains, relatively small bodies, and long and seemingly powerful arms.  They do have some features in the skull and pelvis that are found in members of the genus Homo but not in other Australopiths.  The presence of the latter features would lead some scientists to argue that the new species should be placed in the genus Homo.   However, given the small brains and Australopith-like upper body,  we felt keeping this species in the genus Australopithecus was the conservative thing to do.   It may very well be the immediate ancestor to the genus Homo, and  is certainly a convincing candidate. What about Homo habilis?  I thought it was the ancestor of Homo erectus? Our study indicates that sediba may be a better ancestor.  Until now the fossil record for early members of the genus Homo or transitional australopithecines has been very poor.  Australopithecus sediba may certainly help to clear up some of this “muddle in the middle”.  Homo habilis has been viewed by some to be sort of a garbage can species, with lots of different things thrown in for convenience.  Some researchers have even suggested that it be put into the genus Australopithecus and Au. sediba may be found to support that case. Remember, Homo habilis was described on a mandible of a child, our sample is more complete and we can clearly differentiate our species from that mandible.  Other fossils have only been “associated” with Homo habilis. Did they use tools? They are certainly in the right time period for tool use, and we will be looking closely for artefacts in the assemblage. “Watch this space” is a good answer! Have you found others?  Other than the two? Yes we have, but these are under study or being excavated or prepared. There are babies and adults. Do you expect to find more? Almost certainly.  We have even found more of the skeletons described in the months since submission of the paper. Have you, can you find DNA? We are attempting to search for proteins and DNA at the site. Are there organic remains preserved at the site? Yes, we have porcupine quills, and other organic plant remains.  We are busy searching for and studying possible flesh remains.  Remember, the remains are articulated so we have to take every precaution if there is even the possibility. When will excavations start? We have not excavated yet, only removed miners debris. Once infrastructure is in place, we will begin excavating in-situ, hopefully by the middle of 2011. What other animals have been found with them? A skeleton of a false sabre tooth cat – a dinofelis, some articulated antelopes, an extinct zebra, a wild dog, hyenas, mice and hares.  Many of the animals are as well preserved as the hominids.  There have been no monkeys found with these hominids. Are these Ape-men? People often use the term ape-man or man-ape to describe these bipedal members of the human family tree. Australopithecus sediba is, morphologically, transitional between the early hominids (like lucy, Mrs. Ples and little foot) and the later ones like Homo erectus. Is this the missing link? This is a difficult question and each of you will have to choose how to answer this based on your own personal philosophy of evolution. Au. sediba does appear to be a very good transitional form, maybe the best yet found, between early australopithecines and early members of the genus Homo. Was the site called Malapa before the discovery? No, the site, to our knowledge, had never been known to science until I found it.  I came up with the name in conjunction with the landowners. Are there other sites like Malapa to be found?   Almost certainly, this discovery illustrates as much about what we havn’t discovered as about what we have discovered.  The potential across Africa is great. Are these fossils?  Why aren’t they ‘bones?” They are fossils, they have been replaced by minerals and thus are exact copies of the originals.  The teeth however, are the actual teeth. There is still rock attached to the child’s skull – why?   Due to the fragility of the base of the cranium of the specimen and because we want to leave part of the adhering matrix for future research, we have decided to leave the specimen partially in rock.  We can however visualize this hidden part using scanning technology. The child is the holotype. What is a holotype or type specimen? The single specimen designated as the type for naming a species or used as the basis for naming a species. The female is a paratype.  What is a paratype? Technically  a paratype is each specimen of a type series other than the holotype.  Thus the female is considered part of the type series of Australopithecus sediba. Other “Factoids” They are both arguably the most complete skeletons ever found of an early human ancestor. There are more than 60 scientists from all over the world working on specialized areas of the project. They are certainly the most complete remains of any early hominid in the time period.   We think that they may very well be a direct ancestor of Homo erectus. Matthew was born in 1998. Science is one of the most prestigious scientific journals in the World and is the official journal of the American Association for the Advancement of Science. The work was funded by the South African Government, The University of the Witwatersrand and the Palaeontological Scientific Trust and other donors. Lee Berger found the site using Google Earth. Both skeletons are more complete than the famous Lucy skeleton. The fossils will be on display at Maropeng for ten days after the announcement. The fossils are kept in fireproof safes at the University of the Witwatersrand. Paul Dirks was Head of the School of GeoSciences at the time of discovery. The site is owned by private landowners, the Nash family. How do you pronounce “Australopithecus” .  I use “Australo – pitheecus” making the “e” long (Its what Raymond Dart did.  Most people say “Australo- pith- ecus” with a short “i” and short “e”. Your choice! The site is owned by the Nash family, the fossils are curated by the University of the Witwatersrand and owned by the people of South Africa. Authors First paper Lee R. Berger, Darryl J. de Ruiter, Steven E. Churchill, Peter Schmid, Kristian J. Carlson, Paul H.G.M. Dirks and Job M. Kibii Second Paper Paul H.G.M. Dirks, Job M. Kibii, Brian F. Kuhn, Christine Steininger, Steven E. Churchill, Jan D. Kramers, Robyn Pickering, Daniel L. Farber, Anne-Sophie Mériaux, Andy I.R. Herries, Geoffrey C. P. King, Lee R. Berger