Thursday, 24 March 2011

50 Million year old Reptile skin....splendid!

Today the University of Manchester Palaeontology Research Group  published another paper in the journal Royal Society Proceedings B. The subject of this paper, some beautifully preserved reptile skin. The brightly-coloured image below shows the presence of amide groups – these are organic compounds (building blocks of life) – in the ancient skin of a fossil reptile, found in the 50 million year-old rocks of the Green River Formation in Utah, USA.

This image had never been seen by the human eye, until our team, in this case led by Dr Roy Wogelius and graduate student Nick Edwards, used state-of-the-art infra-red technology to reveal and map the fossilized soft tissue from this beautifully-preserved reptile.

These infra-red maps are backed up by the first ever element-specific maps of organic material in fossil skin generated using X-rays at the Stanford synchrotron in the USA, working in collaboration with Dr Uwe Bergmann at SLAC. This is the same technology that was used to hed light on the chemical ghost of feathers preserved in Archaeopteryx, published again by our team last year in PNAS.

Chemical details are clear enough that we able to propose how this exceptional preservation occurs. When the original compounds in the skin begin to break down they form chemical bonds with trace metals, and under exceptional conditions these trace metals act like a ‘bridge’ to minerals in the sediments. This protects the skin material from being washed away or decomposing further...literally a fossiliferous hard-hat!

Roy is as chuffed as ever about the results, saying, “The mapped distributions of organic compounds and trace metals in 50 million year old skin look so much like maps we’ve made of modern lizard skin as a check on our work, it is sometimes hard to tell which is the fossil and which is fresh.”

Roy is also keen to point out to the palaeontological community that, “These new infra-red and X-ray methods reveal intricate chemical patterns that have been overlooked by traditional methods for decades.”

The new images are compelling, and represent the next step in our research programme to use modern analytical chemistry and 21st century techniques to understand how such remarkable preservation occurs, and work towards discovering more on the fossil chemistry preserved in ancient life.

These new results imply that trace metal inventories and patterns in ancient reptile skin, even after fossilisation, can indeed be compared to modern reptiles. The infra-red light causes sweet vibrations in the fossilized skin, and a map of where these vibrations occur can be obtained from a fossil by using a trick: a tiny crystal (like an old phonograph record stylus) which moves from point-to-point in a programmable grid across the surface.

At each point where the tiny crystal touches the fossil, an infra-red beam that shines through the crystal reflects off of the crystal base, but a small amount of the beam probes beyond the interface- and if organic compounds are present, they absorb portions of the beam and change the reflected signal.

This has allowed our team to non-destructively map large fossils which do not themselves transmit or reflect the beam – a revolutionary process for paleontologists.

Nick Edwards, first author on the publication, said: “The ability to chemically analyse rare and precious fossils such as these without the need to remove material and destroy them is an important and long overdue addition to field of palaeontology.

Here physics, palaeontology and chemistry have collided to yield incredible insight to the building blocks of fossilized soft tissue. The results of this study have wider implications, such as understanding what happens to buried wastes over long periods of time. The fossil record provides us with a long-running experiment, from which we can learn in order to help resolve current problems.

You can learn more about this discover on a video podcast with myself and Roy! Just click HERE

Tuesday, 15 March 2011

...that's funny?

Last week was fun. In a fossil-kind of way...where I had time to sit down and talk with colleagues from across the many departments and faculties at Manchester who make-up the Palaeontology Research Group. From Mike Buckley with his protenacious approach to palaeo, Bill Sellers bounding forward with his locomotion work, Bart van Dongen blasting organic molecules into revealing their identities with his thermal hammer (Pyrolysis unit!) and Roy Wogelius burying his head into surficial processes at the atomic level on squished animals now entombed in rock....precious fossils. I also managed a quick dash to Paul Mummery's x-ray CT emporium, but alas he was off to Oxford with my palaeo-computational colleague Lee Margetts. All these folks and more make-up the unique, some say quirky, group that is the University of Manchester Palaeontology Research Group.

As I have said in prior postings, it is this cross-faculty, multidisciplinary nature of our group that has been the secret to our success. We have all found common ground in long dead beasties...or 'fossils', as some prefer. The most important aspect of this group for me, is what I have learnt from these diverse disciplines, changing the way I conduct, collaborate and manage my research. The fact that I am now happy to talk about the interaction of intense monochromatic synchrotron x-rays with the electronic orbitals of atoms and the associated x-ray induced K-L shell transitions of electrons in fossils,...has simply reinforced how important collaboration is with scientists from outside my discipline. I feel privileged that my knowledge has significantly broadened, but at the same time my understanding has deepened. This is a function of both patient and good colleagues. 

Isaac Asimov, a brilliant (possibly the greatest) science fiction writer and an excellent scientist to-boot, once said, 'The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'

It great working with a group of scientists that at almost every twist and turn in our research we meet curious results that engender a similar Asimovian response. However, the key in our group is having the broad expertise to follow-up with sensible hypotheses that can then be tested and validated, before we go public on those 'funny' moments.

Friday, 4 March 2011

Dear Diary......

On Sunday night I head to Manchester. Once again I face the gauntlet of airline seats so vast that a garden gnome would feel claustrophobic, this combined with an atmosphere so thick that a very sharp knife would be required to even dent the said fuselage smog. The mere thought of airline food has me reaching for my supply of melatonin in the vain hope I will sleep through the optimistic nudge from flight staff asking that I partake in there wares. At times like this, I recall a French PhD student's comment while on fieldwork in the UK. I asked him his view of British Cuisine, his thoughtful reply was, 'Phillipe, this is not cuisine; this is food'...this makes my airline food by comparison look protenacious at best. If....a large 'IF' underlined in bold ink, with large flashing lights...I manage to nod off to sleep, I always end-up precisely folded into my available space like a piece of well-packed, pre-assembly Ikea furniture. The uncomfortable 1 or 2 hours of sleep (at best) is always broken by the announcement of our impending arrival to UK unhelpful one hour in advance of landing...I beg airlines to let us economy class folks sleep till 10 minutes before we start our descent, in the same way that they allow business class passengers! I was not aware that the upgrade correlated with how much sleep you were allowed on a long-haul flight. I often look enviously at the light blue drapes that lead through to the peaceful world of business class, where the dim-lit cabin affords its occupants those precious extra minutes of slumber.

As soon as we hit the tarmac at Manchester Airport, it's off to the University of Manchester to work through my haze of jet-lag. I'm sure that the US military sleep-depravation exercises did not feel this bad. My schedule next week is complex...I say 'schedule' now, given each time I asked a US colleague to share their diary with me, this was met with a frightened expression, often with rapid recognition that another 'British-ism' had crossed their path. A diary is a very private 'dear diary' kind of place in the USA...and is nothing to do with a schedule... pronounced 'sked-duel'. I tried arguing that this was pronounced incorrectly and should always be a 'shed-duel'....this is usually met with disdain and the follow-up of 'So, which 'shool' did you attend to learn English?'. My reply to that is, 'In an English 'shool' in Wells, England...where they taught me to speak English'. Churchill was right, we are 'two countries divided by a common language'.

However, back to my diary! The week will be driven by working through a PhD thesis recently sent to me to proof-read by one of the graduate students I co-supervise at Manchester. This will be punctuated with many meetings, the CT scan of a Gobi dinosaur's twisted vertebra, pyrolysis gas-chromatography mass spectrometry of some dinosaur fossils and a podcast. The latter is with a team from the Royal Society (London)...a function of a research paper that will soon be published in one of their journals. More on the contents of the said paper later, now...I must pack.