Fossil Human Hair

200 000 year old human hair from a hyaena coprolite. Image from Backwell et al. 2009

Over a week ago Lucinda Backwell, who also works at the BPI at Wits, announced the discovery of fossilised human hair that exceeds the previous oldest known hair (from a 9000 year old mummy) by about 200 000 years. Indeed it is so old it might not even belong to our own species but might instead belong to H. heidelbergensis.
The story was picked up by some of our local papers but doesn't appear to have generated much interest in the blogosphere, so I thought I'd timidly foray into the world of palaeoanthropology and discuss Backwell et al.'s paper here.
What adds some iterest to the story is where the fossil hair was found: inside a hyaena coprolite from Gladysvale Cave in the 'Cradle of Humankind' , South Africa (practically next door to such famous sites as Sterkfontein and Swartkrans). Coprolites are, of course fossilised faeces.
Does this mean a hyaena attacked and killed a Homo species in the Late Pleistocene of South Africa? Well I'm sure our ancestors and relatives may have on occasion fallen prey to spotted hyaenas and some of the larger extinct forms. However this fossil does not record such an event. The coprolite was part of a latrine buried in situ in Gladysvale Cave,and the details of this latrine, such as its location inside a cave, small size and well circumscribed boundaries, all indicate that it was made by a brown hyaena (Parahyaena brunnea). Brown hyaenas are rather smallish and are not known to kill humans. Far more likely is that this represents scavenging on an already deceased member of our genus.



A brown hyaena


It was the cave setting that allowed the latrine to be dated. The latrine is sandwiched between two flowstones which contain enough Uranium to be used for Uranium-Thorium dating. This dating was done as part of a larger project by Robyn Pickering, one of the brightest students to come through the BPI in recent years.
Sadly the hairs are preserved as casts in carbonate. No trace of organics are left so we won't be getting any molecular data for 200 000 year old hominids just yet.
By itself that is about all that the paper can tell us. Perhaps if more such latrines could be found we could then survey more scats for fossil hair and discover how frequent such scavenging events occured. Discovery of even older hair, might start to reveal systematic variation and we might even be able to hazard some guesses as to what kind of hairs our more remote relatives bore. For instance we might be able to get a handle on when modern style short fine body hair evolved. The Gladysvale deposits cetainly go back much further in time so the potential for finding australopithecine hair is there.
This also serves to remind us that coprolites are unique microenvironments that have unusual preservation potentials. Ever snce the oldest known mammalian hair was found in Paleocene coprolites, I've thought that coprolites offer us the best chance to find out just when our unique mammalian pelage evolved. I have looked through coprolites from a Middle Triassic synapsid bearing site in the hopes of finding non-mammalian hair but so far no luck.

UPDATE: Randy rightly asked how the ID was made. Mammalian hair is not completely diagnostic to low taxonomic categories. It helped that several specimens were found in the coprolite. Any one hyaena scat usually contains the hair from just one sitting so is not likely to be mixed with other species. Thus there was a sample of several hairs to work from. Only human hairs were found to match the range of variation seen in the fossil hairs (using characteristics such as scale margins, scale spacing, hair width etc.). Other primates came close but most non-human primates produce finer hair. So the ID is a probabilistic one, hence the equivocation in the title of the paper.

L BACKWELL, R PICKERING, D BROTHWELL, L BERGER, M WITCOMB, D MARTILL, K PENKMAN, A WILSON (2009). Probable human hair found in a fossil hyaena coprolite from Gladysvale cave, South Africa. Journal of Archaeological Science DOI: 10.1016/j.jas.2009.01.023

A trip to the Limpopo Province

As I was growing up no African place name seemed more exotic and remote than Limpopo. Actually the Limpopo Province lies just a few hours north of Johannesburg, yet I had never visited it until this week. This is a pity because as it turns out it is a beautifull place indeed. We were on a quick trip up to the Soutpansberg Range to check out claims of metazoan fossils in the Paleoproterozoic Soutpansberg Group (approx. 1700 million years old).


Sandstones and Conglomerates of the Soutpansberg Group

Such a fossil would exceed the next oldest metazoan fossils by about a billion years, and to say I was sceptical would be an understatement. Nevertheless one has to check these things up, just one day someone may really have found something exceedingly significant - but not this time. Nevertheless although no fossils were found (as expected) the day turned into a lovely natural history outing.
At the very start of the hike we saw a large flock of crested guinea fowl, the much rarer cousin of the ubiquitous helmeted guinea fowl, but I could not get a decent picture (although I did get a new tick for my birdlist). We found evidence for leopards in the form of scratched tree trunks (but no leopards of course!). Here are some other shots I took during our search.


It is well known that everything in Africa has thorns but check out these - you'd swear the thing was predatory!

I also snapped this cute little scarab



A story surrounding this little plant is worth relaying.



This is Khat (Catha edulis), a largely East African and Arabian plant well-known for the amphetamine-like drug it produces. Nevertheless it is growing wild all over the Soutpansberg. The place we were staying at used to be a girls school that was closed down after the students discovered this local plant and Khat-chewing became endemic in the school.
After the Soutpansberg we stopped in at Makapansgat on our way back to Jozi. This is a wonderfull little valley that is famous for its limestone caves, one of which (the Limeminer's Cave) has produced remains of the protohuman Australopithecus africanus



Although there are no obvious australopithecus fossils lying around, you can still see this string of vertebrae, left in the cave roof where an articulated sabre-toothed cat was removed (apparently the specimen is at wits but I haven't seen it).



Lastly to end with the palaeo theme, there wasn't just plio-pleistocene fossils to see. The caves themselves were etched into 2 billion year old dolomites with very nice stromatolite fossils.