Synchrotron light reveals 50 million year old hungry caterpillar

A team of palaeontologists, geochemists and physicists have used synchrotron technology to shine a light on ancient fossilised leaves, finding the bite marks of a 50 million year-old caterpillar.

Optical plus X-ray false color composite image (Cu = red, Zn = green, and Ni =blue) of a 50 million year old leaf fossil. Trace metals correlate with original biological structures. Image width ~17 cm.  Also visible are characteristic trumpet shaped feeding tubes left by ancient caterpillars: feeding tube chemistry matches the leaves. Data collected at Stanford Synchrotron Radiation Lightsource (SSRL), a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.
Reproduced with permission of the Royal Society of Chemistry from Nicholas Paul Edwards, Phillip Lars Manning, Uwe Bergmann, Peter Lars Larson, Bart van Dongen, William I Sellers, Samuel M Webb, Dimosthenis Sokaras, Roberto Alonso Mori, Konstantin Ignatyev, Holly E Barden, Arjen van Veelen, Jennifer Anne, Victoria M Egerton and Roy A Wogelius, Metallomics, 2014, DOI: 10.1039/C3MT00242J (link to http://dx.doi.org/10.1039/C3MT00242J).
Optical plus X-ray false color composite image (Cu = red, Zn = green, and Ni =blue) of a 50 million year old leaf fossil. Trace metals correlate with original biological structures. Image width ~17 cm. Also visible are characteristic trumpet shaped feeding tubes left by ancient caterpillars: feeding tube chemistry matches the leaves. Data collected at Stanford Synchrotron Radiation Lightsource (SSRL), a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. Reproduced with permission of the Royal Society of Chemistry from Nicholas Paul Edwards, Phillip Lars Manning, Uwe Bergmann, Peter Lars Larson, Bart van Dongen, William I Sellers, Samuel M Webb, Dimosthenis Sokaras, Roberto Alonso Mori, Konstantin Ignatyev, Holly E Barden, Arjen van Veelen, Jennifer Anne, Victoria M Egerton and Roy A Wogelius, Metallomics, 2014, DOI: 10.1039/C3MT00242J (link to http://dx.doi.org/10.1039/C3MT00242J).
 
25th March 2014, UK: A team of palaeontologists, geochemists and physicists have used synchrotron technology to shine a light on ancient fossilised leaves, finding  the bite marks of a 50 million year-old caterpillar.
 
The group have been investigating the chemistry of exceptionally preserved fossil leaves from the Eocene epoch, found at the Green River Formation in the western USA. They exposed the fossils to synchrotron X-rays 10 billion times brighter than the sun, revealing the fossils’ structure at the atomic level whilst keeping the rock completely intact.
 
The team led by researchers from the University of Manchester, Diamond and the Stanford Synchrotron Radiation Lightsource (USA) have today published their paper in the Royal Society of Chemistry journal, Metallomics.
 
Dr. Nicholas Edwards, a postdoctoral researcher at the University of Manchester and a lead author on the paper said: “Synchrotrons have already shown their potential in teasing new information from fossils, in particular our group’s previous work on pigmentation in fossil animals. With this study, we wanted to use the same techniques to see whether we could extract a similar level of biochemical information from a completely different part of the tree of life. To do that we needed to test the chemistry of the fossil plants, to see whether the fossil material was derived directly from the living organisms or degraded and replaced during the fossilisation process. We now know that plant chemistry can be preserved over hundreds of millions of years.”
Image 3) False colour image of copper (red) and zinc (green) distribution within a modern leaf (A. pseudoplatanus). The distribution of these metals defines the vascular system. Image width ~3 mm. Image from data acquired at the Diamond Light Source, the UK’s national synchrotron science facility.
Image 3) False colour image of copper (red) and zinc (green) distribution within a modern leaf (A. pseudoplatanus). The distribution of these metals defines the vascular system. Image width ~3 mm. Image from data acquired at the Diamond Light Source, the UK’s national synchrotron science facility.
At Diamond, the team used the microfocus spectroscopy beamline I18to gain an insight into the chemistry of these ancient plants. Prof. Fred Mosselmans, Principal Beamline Scientist on I18 at Diamond Light Source commented: “The Manchester-led team have used synchrotron light to gain an insight into the chemistry of these ancient plants. The work shows how the secrets of these prehistoric flora can be unravelled by modern technology.”  
 
By combining the unique capabilities of two synchrotron facilities, the team were able to produce detailed images of where the various elements of the periodic table were located within both living and fossil leaves as well as being able to show how these elements were combined with other elements.
 
The work shows that the distributions of copper, zinc and nickel in the fossil leaves were almost identical to those in modern leaves. Each element was concentrated in distinct biological structures such as the veins and the edges of the leaves. Also, the way these trace elements and sulfur were attached to other elements was very similar to that seen in modern leaves and plant matter in soils.
 
Fine scale false colour X-ray map of the Cu distribution within a modern leaf (left) compared to a 50 million year old fossil leaf (right). Primary, secondary, and tertiary venation comparable to the modern leaf can be resolved in the Cu distribution even after 50 million years of aging. Data acquired at the Diamond Light Source (left panel), the UK’s national synchrotron science facility, and the Stanford Synchrotron Radiation Lightsource (right panel), a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.  Image widths: left ~2.5 mm, right ~10 mm.
Reproduced with permission of the Royal Society of Chemistry from Nicholas Paul Edwards, Phillip Lars Manning, Uwe Bergmann, Peter Lars Larson, Bart van Dongen, William I Sellers, Samuel M Webb, Dimosthenis Sokaras, Roberto Alonso Mori, Konstantin Ignatyev, Holly E Barden, Arjen van Veelen, Jennifer Anne, Victoria M Egerton and Roy A Wogelius, Metallomics, 2014, DOI: 10.1039/C3MT00242J (link to http://dx.doi.org/10.1039/C3MT00242J).
Fine scale false colour X-ray map of the Cu distribution within a modern leaf (left) compared to a 50 million year old fossil leaf (right). Primary, secondary, and tertiary venation comparable to the modern leaf can be resolved in the Cu distribution even after 50 million years of aging. Data acquired at the Diamond Light Source (left panel), the UK’s national synchrotron science facility, and the Stanford Synchrotron Radiation Lightsource (right panel), a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences. Image widths: left ~2.5 mm, right ~10 mm. Reproduced with permission of the Royal Society of Chemistry from Nicholas Paul Edwards, Phillip Lars Manning, Uwe Bergmann, Peter Lars Larson, Bart van Dongen, William I Sellers, Samuel M Webb, Dimosthenis Sokaras, Roberto Alonso Mori, Konstantin Ignatyev, Holly E Barden, Arjen van Veelen, Jennifer Anne, Victoria M Egerton and Roy A Wogelius, Metallomics, 2014, DOI: 10.1039/C3MT00242J (link to http://dx.doi.org/10.1039/C3MT00242J).
Optical (left) plus copper  X-ray false color image (right)  of 50 million year old fossil leaf. False color image: colour intensity indicates relative concentration. Copper is contained within organic compounds derived from the original plant chemistry. Image width ~23 mm.  Data acquired at Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.
Optical (left) plus copper X-ray false color image (right) of 50 million year old fossil leaf. False color image: colour intensity indicates relative concentration. Copper is contained within organic compounds derived from the original plant chemistry. Image width ~23 mm. Data acquired at Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.
Professor Roy Wogelius, also of the University of Manchester and one of the senior authors said: “This type of chemical mapping and the ability to determine the atomic arrangement of biologically important elements such as copper and sulfur can only be accomplished at a synchrotron. In one beautiful specimen, the leaf has been partially eaten by caterpillars and their feeding tubes are preserved on the leaf. We see this behaviour with modern caterpillars. The chemistry of these fossil tubes remarkably still matches that of the leaf on which the caterpillars fed.”
 
The data from a suite of other techniques performed at the University of Manchester has lead the team to conclude that the chemistry of the fossil leaves is not wholly sourced from the surrounding environment as has previously been suggested but represents that of the living leaves.
 
Another reason that these specimens have been so beautifully preserved over millions of years is that they have been preserved by similar elements to those used in modern wood preservatives. Dr. Phil Manning, a senior author on the paper, added: “We think that copper may have aided preservation by acting as a ‘natural’ biocide, slowing down the usual microbial breakdown that would destroy delicate leaf tissues. This property of copper is utilised today in the same wood preservatives that you paint on your garden fence.”
 
Dr. Nicholas Edwards added: “This opens up the possibility to study part of the biochemistry of ancient plants, so in the future it may enable us observe the changes, if any, in the use of metals by the plant kingdom through geological time.”
 
Notes for editors:
 
A copy of the paper, ‘Leaf Metallome Preserved Over 50 Million Years,’ published in the Royal Society of Chemistry journal Metallomics, is available on request.
 
Additional quotes from the paper’s co-authors for use by the media:
 
Stanford’s Dr Uwe Bergmann, the team physicist, said: “Part of what I do involves detailed measurements of the physics of how plants actually harness light energy using transition metals. Here, we are able to show what metals were present, and where, within extremely old plants- and this just may let us understand, eventually, how the complicated physics of life has developed over long periods of time.”
 
Dr Bart van Dongen, a University of Manchester geochemist, said: “There is a sharp contrast in the chemistry of the fossils from that of the rock in which they are entombed – this is true for both the trace metals and the organic compounds. The organic part of the chemistry clearly shows a plant-derived component.”
 
Dr Nicholas Edwards added: “This opens up the possibility to study part of the biochemistry of ancient plants, so in the future, it may enable us observe the changes, if any, in the use of metals by the plant kingdom through geological time.”