Happiness is a bucket of lizards

One of the aspects of academic life in a small research institute is that you are sometimes called upon to supervise student projects that are outside your normal sphere of research activities. Broadening your experience and knowledge can only be a good thing so I welcome this. It also can provide an outlet of unusual activities that can break the monotony of the usual working week.
I am currently supervising one such project that is proving to be quite entertaining. The project is centred upon the almost entirely neglected herpetofauna that occurs alongside the famous Australopithecus fossils of the Cradle of Humankind World Heritage Area.
I found out, much to my surprise, when this project was started that there are no comparative osteological collections of southern african reptiles available in South Africa. So we have had to set about creating one. Fortunately we have been given permission to prepare the skulls of duplicate specimens from the Transvaal Museum collections. I was very pleasantly surprised at the breadth of the taxonomic scope we were supplied with - two specimens of over 40 species from the eastern half of
South Africa. So it was with some excitment that we took consignment of the above pictured and rather full bucket of lizards (Can anyone name the species visible? I'd be impressed if someone managed five or more).
Of course it is the students job to prepare the skulls, but with so many to get through, I've been mucking in and helping with the defleshing, which is surprising satisfying work, especially when you finish with a nice clean skull.

Early Jurassic side-winder - but is it a snake?

Francois Durand's side-winding trace from the Clarens Formation. From Durand (2005.

Discussion about fossil side-winding traces over at Tet Zoo prompted me to get off my butt and actually put something up on this blog.
Its Francois Durand's apparent side-winding trace from the Clarens Formation of South Africa. Not much has been made of this and the only two references to it that I know of are rather obscure so I'm putting it up here to let people know about it.
It certainly looks like a track left by a modern sidewinding viper.



A modern side-winder

Francois made it fairly clear in his presentation of this fossil to the Geoscience Africa conferance back in 2004 that he thought it was made by an Early Jurassic viperid although he only hints at this in the two publications featuring this fossil that I know of. Such an occurence is strongly at odds with the known fossil record of snakes. Even the most primitive snakes don't show up until the Cretaceous, and advanced snakes like viperids don't start radiating until well in the Cenozoic, thus to have a Jurassic Viperid means that just about all tradtional family level clades of snakes have massive ghost lineages stretching back tens of millions of years. The fossil record can be spotty but it ain't THAT bad.
My take is that sidewinding habit may have evolved sporadically from time to time in all sorts of elongate limb-reduced tetrapods when the conditions warranted it. The whole discussion started over the possible sidewinding traces from a Permian, wet muddy, if not aquatic environment that I had a hand in describing.If correctly interpreted sidewinding need not be restrited to dry loose sand, wet sloppy mud might be just as capable of supporting it.
So what was elongate sidewinding tetrapod of the Clarens? We haven't a clue.

references

Durand, J.F. 2004. The origin of snakes. Geoscience Africa 2004. Abstract Volume, University of the Witwatersrand, Johannesburg, South Africa, pp. 187.

Durand, J.F. 2005. Major African contributions to Palaeozoic and Mesozoic
vertebrate palaeontology. Journal of African Earth Sciences 43: 53-82.

So how did it go?

The interview turned out to be quite long after all, and rather enjoyable, although these type of things always make me nervous. We were a panel of three: a catholic preist (whose name I didn't catch due to my hyped up state before the interview)and Jens Franzen, the lead author on the Darwinius paper. Straight off the bat the religious aspect was deflated by the priest stating categorically that the church accepted evolution as the correct mechanistic explanation for the diversity of life and that this was an unguided naturalistic process (I must admit I was surprised to hear a member of the clergy accepting an unguided evolutionary process), as long as god was the creator of the whole show. I was then asked whether or not Darwinius was 'the missing link' urggh! So I attacked the idea of 'missing links' as a valuable concept at all and explained that Darwinius was a primate, like us, but simultaneously quite ancient and distant from us as far as primates go. Towards the end of my little speech I mentioned that its real significance was that it may have been a bit more closely related to anthropoids (monkeys, apes and humans) than to lemurs and thus may have been a very early member of the haplorhine branch of the primate family tree. I was quite equivocal about wether this was a firmly established scientific case. This may have antagonised Jens Franzen a little who went into quite a long discussion about why it was a haplorhine and not a lemur relative. The interview was rapidly in danger of becoming much like a technical question and answer session at a palaeontological conference (mores the pity that it didn't) so the topic was changed and Jens was asked many things about the discovery of Darwinius and its dating. This part of the interview was very informative. Of course the produces wanted more of the religion angle so we were asked our opinion of 'intelligent design'. The prist denounced it saying that it required an intervenionist god to create each lifeform sepparately which is flatly at odds with the evidence. I joined in with some fairly scathing remarks along the lines that it was a scam cooked up by the young earth creationists to get their particular narrow literal biblical interpretation taught as science in American schools. It of course isn't science and it failed in court.
And that is about it. I was told afterwards by several people that I came across clearly and confidently - which is great because I certainly didn't feel it.

UPDATE. Yes there is an MP3, you can download it from here.
I need to say three things here. 1) The preist was Father Anthony Egan - my apologies for not remembering.
2) My voice is not so clear, probably because I was on a cell phone at home.
3) the faint cries heard in the background was Matthew, who decided he wanted milk urgently, sometime during the middle of the interview.

Radio Interview

For those of you in South Africa* - I'll be interviewed on classic FM at 7.30 tonight. Apparently they want a palaeontologist's opinion on the religious implications of Ida, the new fossil primate that everyones all het up about. Religious implications?! There AREN'T ANY! Should be a short interview.

*huh! who am I trying to kid, I'm sure I have no readers left at all after the long dark silence that has descended over my blog

Organisms I Hate: Khaki Bush

Allow me to vent my spleen a little. Although I revel in biodiversity and am fascinated by so many orgnaisms there are some I just plain hate. This is one of them. Khaki bush/mexican marigold (Tagetes minuta)- an unpleasant stinking weed that grows profusely where-ever I need to do field work in South Africa. These tenaciously sticky seeds come off from the seed heads at the slightest touch and embed themselves in any form of clothing. After walking through a field of these you can end up looking like you are covered in black spiky fur.

This was what I bought me out into the field over the weekend - a partial dinosaur skeleton from an odd mudstone lens way up in the Clarens Formation, where dinosaurs are rare. Somewhat disappointingly it turned out to be just another basal sauropodomorph. Oh well.

Finding a fossil and filling a gap: The story of Lyncina onkastoma Yates, 2009

February saw the release of my second paper on the fossil cowry shells of Australia. This one is potentially more interesting for it deals with some of the oldest fossils of this group in Australia and thus sheds some light (admittedly not too much) on the somewhat mysterious origins of the southern Australian endemics.

The modern Australian cowrie fauna is divisible into two great provinces: Those from the north and those from the south. The tropical northern fauna is just a subset of the tropical indopacific fauna and displays little in the way of endemicity. In the south however we have a range of distinctive clades that are endemic to the region. Each of these clades have been given their own genus name: Umbilia, Zoila, Austrocypraea (now a subgenus of Lyncina) and Notocypraea. Notoluponia is a fifth endemic southern Australian cowrie clade but is unfortunately extinct. Phylogenetic analysis has shown that these lineages are not each others closest relatives amongst cowries but each shares relationships with other non-Australian cowrie groups. When did these lineages arrive in Australia and where did they come from? These apparently simple questions are quite difficult to answer. Firstly the fossil record of cowries in Australia is almost entirely restricted to the last half of the Cenozoic. Until recently the oldest cowries did not appear until right at the end of the Oligocene Epoch (about 23 million years ago) whereas the cowrie elsewhere in the world cowries belonging to modern genera can be found back as far as the Eocene and other cowries go back into the Cretaceous. What is more the oldest cowries Australian endemic cowries were clearly members of the endemic lineages and betray little of their origins. Why is this so? Perhaps cowries enterered southern Australia during the early Oligocene. This represents a ‘black hole’ in our record of molluscs in Southern Australia. We have good molluscan faunas from the late Eocene (about 35 million years old) but virtually nothing in the 12 million years or so between these and the late Oligocene appearances. Nor are there any well-preserved molluscan assemblage that fill this gap. Do we just give up at this point?
Of course not. The glaring gap in our knowledge is the result of various workers almost entirely ignoring molluscs preserved as moulds and casts, in favour of those with the original shell preserved. It is true that an original shell is a much easier object to study than a series of moulds and casts (and can be an object of great natural beauty) but if moulds and casts is all you’ve got, shouldn’t we be looking at them?

Enter the Port Willunga Formation. This is a marine unit exposed on the coast of Fleurieu Peninsula, South Australia that dates from right in the middle of that ‘black hole’ in our knowledge of molluscan faunas. It is too porous to preserve mollusc shells but moulds and casts can be found if you look in the right places. This is one of the right places:


Limestone cliffs and shorecut platform just south of the mouth of the Onkaparinga River. Image used with the kind permission of Glenn Alderson. You can see more of Glenn’s pictures here.

Isn’t it beautiful? The Fleurieu coast is full of wonderful little beaches like this one. Apart from fantastic swimming, snorkeling and diving they also have fossils! Wow, who could ask for more? So when spending time with my family in Adelaide I always try to get down to some of the nearby fossil sites.
Late one afternoon when returning from further afield, my father and I stopped off at this beach (precisely for the reason of seeing if mollusc moulds and casts were preserved in the mid Oligocene rocks that crop out there). While wandering around on the rocks I happened to look down and noticed what appeared to be a cowrie internal mould sitting in its external mould. I got pretty excited straight away for I knew this was amongst the oldest known cowrie fossils found in Australia and might belong to a primitive stem-form of one of our endemic lineages. It may not be in the same league as Tiktaalik but it is nice when you set out to find something in palaeontology and you find it exactly where you were predicting it to be. The image below is actually a little volute from the same site – it gives you an idea of how unprepossessing these fossils are in the field.
Nevertheless if you collect the external mould and carefully chip as much of the apertural impression as you can away from the internal mould and glue it to the external mould, you can then take a pretty decent latex peel. This is what I did for my cowrie and this is the result.


I went back to the site two days later and found a further four specimens although none were quite as good as the first which subsequently became the holotype specimen of Lyncina (Austrocypraea) onkastoma.
It is indeed a very early member of one of our endemic lineages: Austrocypraea which I’ve talked about before on this blog. However it is a rather odd Austrocypraea, most noticeably because its fossula (see primer on cowrie shell anatomy here) is smooth and its apertural teeth are short, weak and confined to the anterior end of the shell. Such features are derived among members of Lyncina but are shared to some extent with L. (A.) archeri, the next oldest known member of L. (Austrocypraea). L. (A.) archeri dates to the earliest Miocene Epoch (about 22 million years old) and would appear to be a close relative of L. (A.) onkastoma. If these two early Austrocypraea form a clade diagnosed by specializations not seen in later Austrocypraea, or indeed any other members of the wider Lyncina clade, then it suggests that some diversification had already gone on by the early Oligocene (the age of L. (A.) onkastoma) and that we can expect to find more cowrie species in the Oligocene of South Australia – if only we take the time to look.

Yates, A.M. (2009) The oldest South Australian cowries (Gastropoda: Cypraeidae) from the Paleogene of the St Vincent Basin. Alcheringa 33, 23-31.

Access Denied! When ignorance stops science

I've been back from my field trip for exactly a week now, but I simply haven't found time to blog at all. The field crew was a large one and juggling the group was logistically difficult - especially in the face of having to make up new plans on the spot, when the old ones fell through. What went wrong? I'll tell you.
The trip was originally planned to continue work began last year by a joint Wits - BSP (Munich) expedition with a small contingent (Richard Butler) from the NHM (London). This trip began exploration and collection in the historically rich Herschel district of what is now the Eastern Cape. As a breif primer it was this district that produced the holotypes of Melanorosaurus readi, Plateosauravus cullingworthi, Heterodontosaurus tucki, Blikanasaurus cromptoni and Stormbergia dangershoeki as well as a some of the best specimens of Massospondylus carinatus and the spectacular complete skeleton of Heterodontosaurus (not the holotype).
Politically the area is a difficult one to work in because historically it was an isolated fragment of the Transkei, a 'homeland' for black south africans - not to dissimilar to Indian reservations in the US. Although integrated with South Africa in 1994, the Herschel district has remained in dire poverty and partly under the old governance of cheifs and big men. The national government has however set up wards and councillors who are supposed to work together with the traditional rulers.
It was some trepidation that our team stepped into this region, with the view of exploring this territory. One of our goals was placing new positively associated and identified dinosaur specimens on accurately measured strat sections to better understand dinosaur distributions through the Elliot. We also just wanted to see what else we could find to flesh out the fauna of the Elliot - many taxa are still known from single specimens and new discoveries are made often enough to indicate that the discovery curve for the Elliot is not yet near a plateau.
We decided that Blikana Mountain - magnificent area of near continuous outcrop would form the basis of our search effort. After contacting the local councillor responsible for Blikana and meeting with her we were granted permission to explore and excavate.
Although the region has a fearsome reputation we found the locals friendly, somewhat bemused by our interest in stones and eager to help. Many knew about fossilised bones and told us about likely sites.
Thus when we returned this year we were hoping this good relationship would continue. Alas it was not so.
Immediately upon arrival we knew something was up. We had to meet with the councillor in town and under no circumstances set foot on Blikana. It turns out that the councillor was not going to grant us access because she claimed some residents of the area thought we were digging up the bones of their forefathers and robbing their graves and she supported their concerns. It seems the problem started when we showed the councillor herself some of the dinosaur bones we were looking for and gave them to the local school for educational purposes (isolated surface bones are generally abundant). This part of South Africa must be one of the very few places on Earth where the general population has never heard of dinosaurs. Sadly the councillor was unwilling to listen to our explanation that these bones predated any human and were certainly not hers or anyone elses ancestors. Reason didn't seem to work when we pointed out that these bones patently couldn't even fit inside a human body. I suspect that there was more to the problem than was being stated, perhaps we were a difficult problem and the councillor simply wished us to go away. Afterall the elections are near, there has been a split in the ruling party and tensions are running high. No politician wishes to stick their neck out at times like these. Another argument levelled at us was that we were giving no benefit to the locals. Here we are fighting an insidious meme that unfortunately has deep roots in South Africa, that is science = colonial imperialism. Sadly we could not convince her that our science uncovered important natural heritage for all South Africans, indeed all people of the world to share.
In anycase the exposures of the Elliot Formation are simply too good to ignore (they are the best in South Africa), it seems we will have to embark on a campaign to raise local awareness of the important natural heritage that lies beneath their feet.