The Earliest Australopithecines
Orrorin is a new fossil from Kenya, 6 Ma in age, said to be appropriately ancestral-hominid in its morphology, and classified as the earliest hominid by its discoverers. Details of the femur structure indicate that Orrorin was already bipedal, and other characters would allegedly place Orrorin as a more direct ancestor of Homo than Australopithecus afarensis (Lucy). In any circumstances, these claims would spark discussion among paleoanthropologists.
Orrorin could be discussed amicably. Instead, the personal chemistry among the current bunch of paleoanthropologists has set off an undignified, unethical fight. Paleoanthropologists are the worst-behaved of paleontologists, in any case, and they have been for so many decades that it is deeply embedded in their culture; and Richard Leakey seems to be a world-class example. I've been on the receiving end of his tongue myself, and I'm not even in the field! (I think he insulted me just to keep in practice!) "A gentleman never offends unintentionally" (Oscar Wilde).
The new skull from Chad: Sahelopithecus
The hominid find of the century (so far). A new and well-preserved skull from 7-8 Ma, from Chad was reported in July 2002. It should alter the story of the origins and early evolution of hominids. Described in two papers in Nature: Brunet, M. et al. 2002. A new hominid from the Upper Miocene of Chad, Central Africa. Nature 418, 145-151; Vignaud, P. et al. 2002. Geology and palaeontology of the Upper Miocene Toros-Menalla hominid locality, Chad. Nature 418, 152-155. Bernard Wood's commentary is a triumph of opinion and assertion over logic and evidence: I'll discuss that at more length later.
Nature has made it freely available on the Web, along with other "classics" of hominid paleontology it has published over the years. Congratulations and thanks!
National Geographic News, the fullest "pop" account with a picture gallery.
In 2005, a new reconstruction of the skull was published. The authors argued that Sahelanthropus really is a basal hominid, and also that it probably walked upright.
BBC News OnLine
National Geographic News. They shouldn't call it the oldest human!
Blog by John Hawks of the University of Wisconsin. Hawks is dubious that Sahelopithecus is clearly a hominid as opposed to a panid ("chimp"). I suspect he thinks it is so close to the split between humans and chimps that we can't tell yet which branch it is closer to, and it may not matter, considering that you wouldn't expect it to have features like a modern chimp or a modern human: it would be the closest fossil yet to the common ancestor.
The paper is Zollikofer, C. P. E., et al. 2005. Virtual cranial reconstruction of Sahelanthropus tchadensis. Nature 434: 755-759, and comment, Science 308: 179-181. Nature papers are hardly ever generally available on the Web, but the Science comment should be on the Web here soon.
Ardipithecus: New pieces of Ardipithecus, announced July 2001
Knuckle-walking in early australopithecines. Features of the wrist of early Australopithecus are claimed as the traces of "knuckle-walking" in their (and our) ancestors. No real surprise: knuckle-walking is the way that today's chimps and gorillas get around on the ground in a quadrupedal mode, with the fingers curled under into a fist, and stress passed upward into the lower arm. Australopithecus was already walking upright, of course. Frankly, I don't see the big deal here. What worries me is that the authors allegedly claim that knuckle-walking is a feature of African apes only. Well, I've seen orangs knuckle-walking, and have photos to prove it. Knuckle-walking is probably deep within anthropoid lineages, which spoils this part of their story, but doesn't alter their demonstration that our ancestors knuckle-walked.
Footprints at Laetoli, and bipedalism
Australopithecus in South Africa
South African Australopithecus as old as 4 Ma? Well, maybe. This is a new technique of dating, the assumptions are many, and the cave geology in these deposits is very complex. I and others are likely to wait, perhaps a long time, before accepting this. The paper is in Science, April 2003. Partridge, T. C., et al. 2003. Lower Pliocene hominid remains from Sterkfontein. Science 300, 607-612, and comment, p. 562. News articles:
Article from the New York Times featuring the discovery of Little Foot. You might think that this discovery was important. However, by 1998 the University of the Witwatersrand had told Ron Clarke that he was going to be fired because his research was "old-fashioned"!!! By outstanding detective work, Clarke reasoned that the rest of "Little Foot" might be found at Sterkfontein....
New York Times, December 1998
Update on Clarke's research, March 1999, from the New York Times.
Finding the hand of the specimen; this is a news report from BBC News OnLine, Wednesday, 15 December 1999. Ron Clarke's research article is available at the Web site of the South African Journal of Science, but you have to load Adobe Acrobat to read and print it.
Sterkfontein has been declared a UNECSO World Heritage Site because of its status as a "cradle of mankind" .
A. africanus, with links to images of specimens
The anatomy of Australopithecus africanus: Article from the New York Times, commenting on the discovery that the arms of A. africanus are very long. Features the research of our very own Henry McHenry of UC Davis.
Based on the physical features of its jaws and teeth, Australopithecus africanus (and all other australopithecines) had been interpreted as vegetarian. However, you are what you eat, geochemically, and as an animal forms tooth enamel, that tooth will then carry the carbon isotope pattern of its food. It turns out that tooth enamel from A. africanus is chemically not like tooth enamel from vegetarians at South African sites. Instead, it is more like that of the local hyenas, suggesting a significant component of meat in the australopithecine diet. (The real story is more complex, but that's a fair summary.) The most likely interpretation is that A. africanus was an opportunistic feeder who managed to catch a fair number of little vegetarian animals, or was able to scavenge a fair number of pieces from the carcasses of vegetarians.
Robust australopithecines are currently being re-assessed, and all this section may change. For example, many experts now call all robust australopithecines Paranthropus.
News update, April 2000. Discovery of new Australopithecus robustus skull in South Africa.
Here are some images of robust australopithecines:
A news update: A new skull of A. boisei may show that it is not a separate species. If it is not, it should be called A. robustus.
Claim that Australopithecus robustus used tools. In January 2001, a report suggested that A. robustus used specially selected bone tools to dig into termite mounds. (Termites are very nutritious, it is said: twice the calories of steak!).
However, if you read the actual research paper (Blackwell and d'Errico 2001), you will find two separate lines of thought.
That says to me that the case is not as clean as the news reports would have it that Australopithecus robustus was either making the tools or eating termites. I think it would be wise to wait for more evidence here!
- There are specially selected bone tools at three South African sites that were undoubtedly used to dig into termite mounds.
- Homo is found at two of the three sites, and A. robustus is found at all three: that indicates, but only weakly, that A. robustus, rather than Homo, made the tools.
A new report from October 21, 2003 described tools associated with butchered bones, and they are at 2.6 Ma. This is more evidence that some Australopithecus, probably A. garhi, was technologically advanced. This is not a huge breakthrough (it pushes back the date by 100,000 years or so), but any site of this quality is welcome. The New York Times took its article off its free material.
Previous stories on A. garhi and its tools and inferred behavior:
The Earliest Tools
Note that the earliest tools were probably made by a species that we would place at present in Australopithecus. This is a hot area of research: be prepared for surprises (and arguments)! However, there is a growing appreciation for the technological skill of these first stone tool makers.
February 17, 2004. Australopithecus had a more advanced brain than we had thought. BBC News OnLine.
Page last updated, October 23, 2006
Links last checked September 29, 2005.
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