Archive for July, 2008

Everything people ask me about dinosaurs, they learned from Jurassic Park

Jurassic Park has a lot to answer for (both positive and negative) with respect to palaeontology and as someone working on both dinosaurs and pterosaurs you can imagine that it comes up in conversation sooner or later with just about everyone I have met (outside of the profession, and more than a few inside too) in the last (*gulp*) 15 years. Both the initial film and the two sequels (plus the books, computer games, toys etc.) have entered popular culture in a way far beyond even King Kong or 1 000 000 years B.C. ever did. While it certainly generated a new wave of interest in palaeontology, provided direct funding for research through the Jurassic Foundation, and made things like ‘Walking with Dinosaurs’ possible though the technological advancements made in computer imaging, sadly a few things I wish had been different. Or more specifically people would stop asking me about.
Continue reading ‘Everything people ask me about dinosaurs, they learned from Jurassic Park’

Stolen fossils returned

This story cropped up on the BBC today and I thought it was worth mentioning. Basically a bunch of fossils from Argentina that had been illegally exported were confiscated in the US and sent back (after a ‘slight’ delay).

However, what the story fails to mention is that just repatriating such finds is only the start of the story. Some poor museum now has to sort through the material and try and work out what came from where and when. If there were significant dinosaur fossils in there it is likely that some are chimeras or dodgy fakes. While anything can be used to a limited degree for scientific research, when you do not know the providence of a fossil it greatly limits what you can say about it. You can’t be sure it’s not a mixture of several individuals or even several different species and you do not know where it is from (in time or space). Once a fossil passes out of a scientist it is very hard if not impossible to know its history and that makes it hard to use for research. We should give thanks that this material has been recovered, but how much of it will turn out to be of genuine value is another thing entirely.

It is also worth mentioning just how rare an event this is. While of course these things do not always make the news, I honestly can’t remember the last time it was reported (in the media or professional circles) that a significant amount of fossils had been recovered from an illegal source. Restrictions on fossil dealing are very tight in a number of countries with important fossil beds (including China, Brazil, Argentina and Germany) and yet pieces are often available direct from fossil dealing websites. Despite the obvious origin of some specimens, listed as ‘origin unknown’ or the mere fact that they have already extracted them from the country make them difficult to have seized or sellers banned. This material is lost to science in general as it disappears into private collections or if it is ‘returned’ to public hands it often has to be paid for and again, exact providence is unknown.

In short, it is good that this material is returned, but far better that it was never taken. Laws need to be stepped up and pressure applied to illegal collectors and dealers. There is only one of any fossil and even just taking it from the parent country and reduce it to a fraction of its scientific value.

Helmut Tischlinger – the King of UV

The name ‘Helmut Tischlinger’ is probably unknown to almost any one who does not work on pterosaurs or in German vertebrate palaeontology, yet he deserves huge recognition for his work, and that work is very important. You have, whether you know it or not, probably seen some of his images at one time or another and if so were probably struck more by their artistic beauty than the actual scientific information they contained, though of course the latter is the reason for their existence. You might be fooled into thinking I am talking about a palaeo artist here, but in fact Helmut’s work is photographic, and more importantly he does not work in natural light, but in the world of ultraviolet.

UV picture of a distal Rhamphorhynchus wingHelmut’s pictures if you have seen them are immediately obvious as they are typically in vivid shades of blue, yellow or green and highlight beautifully both bones (or shells) and especially soft tissues like pterosaur wings, feathers, muscles and more. Most recently he provided the images for the description of Juravenator, but before that has photographed almost every specimen of Archaeopteryx, numerous pterosaurs (including the Dark Wing and new Anurognathus) and many, many other fossils from the Solnhofen beds of his native Bavaria. If you have Dave Unwin’s recent book on pterosaurs, or Luis Chaippe’s recent one on birds you will certainly have come across his work.

You have probably missed Helmut’s work because although he is often credited for his photos and appears as an author on plenty of papers (in addition to authoring his own) mostly he writes in German and the papers are directed to German journals. However, such has been his contribution to palaeontology that he was recently deservedly awarded an honorary PhD from the University of Munich. Part of my reason for doing this piece is to promote his work as it is not as widely known or appreciated as it should be – there are important things hidden in UV light that researchers and preparators alike need to be aware of.

Helmut has been called the ‘King of UV’ by several of his friends and while this is meant as a good-natured joke, it is also true. It has been known for over a century that many fossils fluoresce under ultraviolet light and that especially soft tissues can look very different to the background matrix in some cases. However, with low powered lights and primitive photographic techniques and taphonomy still in its infancy, it was more of a curio than a useful scientific method. UV continued to be used over the years with techniques improving, but little ever entered the literature and so it is hard to tell exactly what it brought if anything to the palaeo table. You could maybe tell there was something there, but with no detail and no effective way of capturing it on film. [Photo of Helmut (2nd L) courtesy Markus Moser].
Helmut (2nd L)

As you can see through, things have certainly changed and Helmut is responsible for pretty much everything that has been produced in the last ten years or so. The equipment he uses is either custom made or built by him himself (in the case of his filters) so its not like people can just replicate his work – the act of setting the lights, filters, exposure times and more is every bit as much and art as a science and experience is key. Each piece of rock and bone or tissue will react differently to different light wavelengths and will be captured differently with varying exposures and filters. The right combination is needed to show up whatever you are interested in and multiple frames are needed to capture all of the available details.

Lots of different things show up (of course depending on the preservation) in UV and more importantly look very different that under natural light. While the photos are beautiful in themselves, the technique can be used to show up bony sutures that are otherwise hidden, and especially to separate bones or softs from the underlying matrix or each other. Often the two can barely be told apart they are coloured so differently, but when one shows up blue and the other white, life becomes much easier! The work on the dark wing Rhamphorhynchus wing tissues was greatly facilitated by photos that could separate the blood vessels from the muscles tissues because they showed up in different colours with the right filters. Chitin and calcerous carapces do not escape either, and plenty has been done on the invertebrate fossils of the Solnhofen too and shown up new features, or cleared up confusions. Invisible tissues and patterns can even be revealed as tissue soaks into the matrix. The rock might not loo and different in shape or structure, but under UV the clear outlines of scales can appear, traces of lost feathers or skin that remain present but hidden. Sadly what is often revealed is that material probably was present but invisible to the naked eye was prepped away to reach the bones (just look at what happened to the Berlin Archaeopteryx when they knew!).

UV image of the Dark Wing
That is lost forever now, and while much new work in Germany is at least being done in conjunction with UV light in order to search for and preserve soft tissues, the same is sadly not the case in other places. If was for this reason that Xu Xing and I (together with Zhou Zhong-he and Zhang Fu-cheng) brought Helmut to Beijing this year. You can imagine my reasoning – if soft tissues have been happily prepared away on all kinds of pterosaurs and others in the Solnhofen, what might be happening with the Jehol fossils? Might critical stuff be being destroyed, and might many new features remain hidden in those that have already been studied.

Helmut spent many long and dark hours in the IVPP basement setting up his travel kit and shooting all kinds of fossils looking for traces of hidden structures, lost parts and new information as well as trying to tease his filters and lights into showing up what might just be there. For the answers to those questions you will have to wait for us to start the work or writing up the results, but from that you should be able to work out that his trip was not wasted.

While the skills and equipment necessary for this kind of work are obviously highly specialised (not to mention the patience where each frame might need an hour long exposure) and not cheap to acquire (either in costs or actual time and effort devoted to it) this really is a technique that needs to be pushed hard. Palaeontology is more than just bones, but as Helmut’s work reveals, much of the stuff beyond bones is either invisible, or in the past was erased before we even had a chance to find it. Hopefully this post has gone a very small way to promoting not just his work, but more importantly his methods.

One final note, all of the photos here are ‘on loan’ so to speak and belong to Helmut, please don’t go copying them, downloading them or linking to them without permission. I don’t have access to software to protect or watermark them, so I’m relying on people being nice and reading this.

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