Malapa Fossil Site, Cradle of Humankind: Difference between revisions
m sp, date & link fixes; unlinking common words, replaced: human → human, September → September, March of 2008 → March 2008 (2), August 15th, → August 15, (2), 2008 → 2008, South Africa → South A using AWB |
Profberger (talk | contribs) mNo edit summary |
||
| Line 45: | Line 45: | ||
==References== |
==References== |
||
{{reflist}} |
{{reflist}} |
||
==External links== |
|||
{{wikispecies}} |
|||
{{Commons category}} |
|||
*[http://www.profleeberger.com/australopithecussedibaimages1.html Free Images and resources about "Australopithecus sediba" and Malapa for Educators and Students] |
|||
{{coord missing|South Africa}} |
{{coord missing|South Africa}} |
||
Revision as of 08:48, 26 December 2010
| Malapa Fossil Site, Cradle of Humankind | |
|---|---|
  Location in Gauteng | |
| Location | Gauteng, South Africa |
| Nearest city | Muldersdrift, South Africa |
| Area | less than 100 m (330 ft) |
| Established | Discovered 2008 |
| Governing body | Cradle of Humankind Management Authority and Private Landowner |
Malapa is a fossil-bearing cave located about 15 kilometres (9.3 mi) Northeast of the well known South African hominid-bearing sites of Sterkfontein and Swartkrans and about 45 kilometres (28 mi) North-Northwest of the City of Johannesburg, South Africa. It is situated within the Cradle of Humankind World Heritage Site.
History of investigations
In March 2008, Lee Berger of the University of the Witwatersrand, South Africa, undertook an exploration project in the Cradle of Humankind World Heritage site outside of Johannesburg, in order to map the known caves identified by him and his colleagues over the past several decades, and to place known fossil sites onto Google Earth so that information could be shared with colleagues.[1] The area is important as nearly a third of the entire evidence for human origins in Africa comes from just a few sites in this region, and the region is arguably one of the most explored areas in Africa for evidence of human origins, having been investigated continuously since the first discoveries were made there in 1935[2].
At the beginning of this project, there were approximately 130 known cave sites in the region and around twenty fossil deposits[1]. By July 2008, the pattern of cave distribution seen on Google Earth by Berger as well as the recognition of what these deposits looked like from satellites and significant amounts of searching on the ground had led Berger to discover almost 500 caves that scientists had not plotted or identified previously[1]. Included in this were more than 25 fossil sites that had been unknown to science, all in probably the most explored region in Africa. Berger brought in geologist Paul Dirks, at that time Head of the School of GeoSciences at the University of the Witwatersrand, to lead the geological aspects of this exploratory project[1]. In late July, Prof. Berger noted in Google Earth a series of caves running along a fault that pointed to a blank area in the region, an area that appeared to have clusters of trees that typically marked cave deposits[1]. On the 1st of August he dropped off Prof. Dirks to map the recognized cave system and proceeded into the uninvestigated area with his dog Tau, a ridgeback who accompanied him on almost all his explorations[1]. Almost immediately he discovered a rich fossil site that was unknown to science, in the vicinity of more than three dozen caves that had been apparently unrecognized by previous researchers[1]. On August 15, Prof. Berger returned to the site with his post-doctoral student, Dr. Job Kibii and his 9 year old son Matthew. Within minutes, Matthew had discovered the first remains of early human ancestors - a clavicle, or collar bone. On the opposite side of the block Prof. Berger quickly discovered a jawbone with a canine tooth of a hominid. The find would soon be prepared and identified as part of a partial skeleton of a juvenile hominid, around 9 – 13 years of age[3].
On September 4, 2008, Berger returned to the site with more than a dozen colleagues where Berger discovered a second partial skeleton of an adult female[3].
Recovered fossils
The site has produced arguably one of the most complete assemblages of early human ancestors ever found, including arguably the most complete skeletons of early hominids yet discovered and by far the most complete remains of any hominid dating to around 2 million years ago[3]. Over 130 elements have been recovered to date[3]. The partial skeletons are initially described in two papers in the journal Science by Berger and colleagues as a new species of early human ancestor called Australopithecus sediba (sediba meaning natural spring or well in Sotho) [3]. The species is suggested by the authors to be a good candidate for being the transitional species between the southern African ape-man Australopithecus africanus (the Taung Child, Mrs. Ples) and either Homo habilis or even a direct ancestor of Homo erectus (Turkana boy, Java man, Peking man).[4] The species has long arms, like an ape, short powerful hands, a very advanced pelvis and long legs capable of striding and possibly running like a human.
The skeletons are found among the articulated skeletons of a sabre-toothed cat, antelopes and even mice and hares[2].
Geology
They are preserved in a hard, concrete-like substance known as calcified clastic sediments that formed at the bottom of what appears to be a shallow underground lake or pool that was possibly as much as 50 metres (160 ft) underground at the time[2]. It is not known how these skeletons came to be in this pool, but it appears that they may have taken a significant fall[2][4]. No carnivores or scavengers reached their bodies[2].
Age of the deposits
The fossil was dated using a combination of palaeomagnetism and uranium-lead (U-Pb) dating by Andy Herries (UNSW, Australia), Robyn Pickering (U. Melbourne, Australia) and Jan Kramers (U. Johannesburg). U-Pb dating of the underlying flowstone indicates that the fossils are not older than ~2.0 Ma. The occurrence of species of animal that became extinct at ~1.5 Ma indicate the deposit is not younger than 1.5 Ma. The sediments have a 'normal' magnetic polarity and the only period between 2.0 and 1.5 Ma when this occurred is the Olduvai sub-Chron between 1.95 and 1.78 Ma..[2] The fossil is suggested to be closer to 1.95 Ma based on the stratigraphy at the site[2].
See also
References
- ^ a b c d e f g Patel (April 8, 2010). "Wits scientists reveal new species of hominid". University of the Witwatersrand.
- ^ a b c d e f Dirks; et al. (2010). "Geological Setting and Age of Australopithecus sediba from Southern Africa". Science.
{{cite journal}}: Cite journal requires|journal=(help); Explicit use of et al. in:|author=(help) - ^ a b c d e Berger; et al. (2010). "Australopithecus sediba: A New Species of Homo-Like Australopith from South Africa". Science.
{{cite journal}}: Cite has empty unknown parameter:|coauthors=(help); Cite journal requires|journal=(help); Explicit use of et al. in:|author=(help) - ^ a b "Geologists Uncover Major Ancient Human Ancestor in South Africa". National Science Foundation. April 8, 2008.
External links
