The South African Department of Science and Technology (DST) today hosted a seminar on palaeontology to review the work funded by South Africa and China in this field.
The China and South Africa have agreed to arrange joint workshops every year, and to use the workshops to review progress and exchange information about research being conducted on fossils in the two countries.
South African participants included officials and representatives from the DST, the University of the Witwatersrand, the National Research Foundation, and the South African Agency for Science and Technology Advancement.
Their Chinese counterparts included officials and representatives from the Institute of Vertebrate Palaeontology and Palaeonthropology and the Chinese Ministry of Science and Technology.
Several presentations were made. Professor Lee R Berger of the Institute for Human Evolution, School of Geosciences, at Wits University, delivered a presentation on the two skeletons named Australopithecus sediba, the two most complete early human ancestor skeletons yet discovered.
The Malapa site, designated UW 88, was discovered in 2008 by Professor Lee Berger during the course of a systematic survey of the Cradle of Humankind region. The area, long known for its rich fossil deposits, lies just outside the metropolitan area of Johannesburg, South Africa, and includes the famous Sterkfontein cave.
On 15 August 2008, the first remains of an early hominin were discovered at the site by Matthew Berger, Professor Berger's son who was nine years old at the time.
Since this initial discovery, the site has yielded one of the most remarkable treasure troves of early hominin remains ever discovered, including the two most complete skeletons of early hominins yet recovered from Africa.
One skeleton is that of a juvenile male that was approximately 12 years old when it died and the other is the skeleton of an adult female who died at about the same time. The fossils date to nearly two million years ago.
In April of 2010 it was announced that these skeletons were of a previously unrecognised species of early human ancestor: Australopithecus sediba.
The announcement of these finds has stimulated enormous public interest around the world, as well as renewed scientific interest in the Cradle of Humankind.
The find has also provided what is potentially a new and important link between early African human ancestors and the immediate ancestor of modern humans: Homo erectus. Specimens of Homo erectus have been found in China and the Far East.
Australopithecus sediba offers a tantalising and remarkably complete glimpse into one of the most poorly known periods in human evolution, namely the two million years old transition between the so called ape-men (the australopithecines) and our genus, which is called Homo.
After Professor Berger gave his presentation Dr Jacqueline Smilg, Principal Radiologist at the Charlotte Maxeke Johannesburg Academic Hospital, South Africa, and Lecturer at the Department of Diagnostic Radiology, at Wits University, gave a talk.
CT scanning has been used for medical diagnostic imaging since the early 1970s. Since the mid-1990s the process has been applied to the study of fossils with the development of computer assisted 3D-analysis programmes.
In the past, fossils would be scanned with a CT scanner and the digital images produced would help paleoanthropologists to reconstruct the fossils electronically. The 3D-reconstruction programmes provide tools to display, manipulate and measure fossil specimens on screen.
Recently a team studying the Malapa fossil site in South Africa initiated a project examining the usefulness of CT technology to image fossil containing rocks before their preparation. This is an attempt to identify fossils hidden within blocks of rock.
Previous attempts to use CT imaging on rocks from other South African sites yielded disappointing results. This was due to such factors as rock density and unmanageable artefacts from metallic inclusions.
With improved technology, more sophisticated machines and better post-processing tools, the latest work has shown encouraging results.
The methods employed have resulted in the discovery and identification of early hominid fossils, attributable to Australopithecus sediba, that were not visible on the surface of individual blocks. This improved the search for these rare fossils.
The methods that were used also helped to remove the additional area of chance discovery, thus reducing the potential that fossils would be damaged through accidental encounter during routine preparation. They also minimised the chance of completely missing a fossil during preparation.
The results could significantly change the way fossil discovery is done. In the past, fossil bearing rocks were subjected to lengthy and costly manual preparation techniques and scientists had no idea what the outcome of their work would be. Now, with the use of up-front CT scanning, blocks can be prioritised to maximise outcomes.
This technology opens up the potential for eventual "virtual preparation" techniques that could be applied to other fields of palaeontology.
A further presentation on the South African "Cradle of Humankind" was made by Dr Amanda Esterhuysen, a senior lecturer in the Department of Archaeology at the University of the Witwatersrand.
"The Cradle of Humankind opens windows onto many pasts: onto the origins and evolution of humanity; onto the ever expanding frontiers of science in the fields of palaeontology, geology and genetics; onto the remarkable group of scientists that drove these frontiers forward; onto several of the most momentous and formative moments of South Africa's more recent history, including its peopling by its present African population; and onto the often strange, sometimes tortured psyche of a large slice of white South Africa after it came to dominate the sub-continent in the late nineteenth century.
"The Cradle of Humankind can thus deservedly claim a special status among the heritage sites recording South Africa's past, offering as it does a privileged vantage point from which to understand what it means to be human and what it meant and currently means to be South African".
This paper presented a wider history of the Cradle of Humankind and of the palaeosciences in South Africa. The fourth presentation was given by Dr Job M Kibii, a researcher at the Institute of Human Evolution. The title of his talk was "Australopithecus sediba: A Taphonomic Perspective".
The well preserved, minimally damaged and partially articulated sediba skeletons are argued to have been accumulated through a death trap. The diverse mammalian faunal assemblage associated stratigraphically with
Australopithecus sediba is characterised by a number of partial skeletons and or antimeric sets of bones across all taxonomic groups.
Analyses of bone surface modification reveal no biotic bone accumulating agent damage. In addition to other taphonomic data, these observations suggest that the remains of animals recovered in context with Australopithecus sediba are from individuals that died in the same cave either having accidentally fallen through vertical shafts that connected the cave to the ground surface or became trapped and were unable to escape after intentional entry.
The discovery of articulating bone specimens and antimeric sets of bone specimens, in addition to paucity of bone surface modification, suggest that the assemblage was accumulated through death trap.
Discovery of numerous cranial and postcranial elements from all the regions of the skeleton with minimal or no biotically derived modification suggest individuals may have fallen to their death into the cave.
Low structural density skeletal elements, such as ribs and vertebrae, more so those deriving from juveniles, without signs of carnivore modification indicate that some of the carcasses, and or carcass parts were not brought in by carnivores.
The high incidence of cranial elements belonging to large carnivore may have most likely resulted from individuals dying within the cave. Some carnivore individuals may have exploited the cave as denning sites, while others may have fallen into the cave and died there.
The fossil accumulations may represent death traps, where animals fell into a steep shaft or aven from which they could not escape. No tooth marks have been observed on the exposed surfaces of the MH1 and MH2 bones, and this, combined with evidence of at least partial mummification of the right hand and forearm bones of the MH2 specimen, suggest that it was neither accumulated by carnivores, nor ravaged by them after having fallen into the cave.
Antimeric pairs of bones of various taxa (including bovids) and articulating skeletal elements indicate a death-trap scenario in the absence of scavengers.
Liu Wu of the Institute of Vertebrate Palaeontology and Palaeoanthropology, Chinese Academy of Sciences, Beijing, China, concluded the seminar by giving an overview of some recent collaboration in palaeoanthropology between China and South Africa.
Starting in 2008, exchanges and collaborations of palaeoanthropology between the countries were carried out in several aspects. This included personnel exchanges, joint research, information and reference exchanges, communications between the two sides and training for personnel.
Tomorrow, 30 September 2010, Deputy Minister of Science and Technology, Derek Hanekom, will be the keynote speaker at the closing ceremony that will mark the end of the Heritage month at the South African Pavilion.
