This week the journal Science online is announcing a breakthrough in determining what birds and other prehistoric animals looked like 100 million years ago. Dr. Phil Manning was part of the international team who made the discovery; he is an associate professor and heads the Palaeontology Research Group at the University of Manchester (U.K.) and is currently on sabbatical at the University of Pennsylvania (USA). The research team also included Dr. Roy Wogelius of the University of Manchester and Dr. Uwe Bergmann from the Stanford Synchrotron Radiation Lightsource.
The discovery will be featured in “Jurassic C.S.I.: In Living Color,” premiering Thursday, July 7, at 10 p.m. ET/PT on National Geographic Channel (full series to air this August). Manning, who will host the new series, talks here about the discovery’s significance.
Q: How were you able to shed new light on how long-extinct birds — and by extension their relatives, the dinosaurs — looked?
A: For the first time, we are able to chemically map the presence of specific elements and compounds that correlate with the residue of pigment in several extinct species. Not only can we map the presence of specific pigments but we also can map their concentration, so this enables us to generate an image of the distribution of pigment patterning in extinct animals. The presence of pigment must not be confused with color, as even with a specific pigment being recognized, there are/were many factors that contribute to an organism’s entire color palette. Our team has unequivocally resolved the presence of eumelanin pigment, so we still have much work to do, but this is a major breakthrough.
Q: You applied a sophisticated technology to find chemical traces of eumelanin. What is the significance of eumelanin?
A: The technique we applied was called Synchrotron Rapid Scanning X-Ray Fluorescence (SRS-XRF). This allowed us to first map the chemistry of living species’ tissues, including skin, scales, feathers and hair, to provide us with information to relate to extinct species. Using the SRS-XRF, we were able to map the chemistry of fossils, which we then compared the chemistry of the living species’ samples. We were very pleased that the chemistry has remained relatively unaltered in some cases. Eumelanin has a copper atom at its structural heart, allowing us to map its presence, via its distinctive signal. Eumelanin is possibly the most important pigment in living species, and our study clearly identified this pigment’s presence and distribution in several extinct species. We can now use this copper-coordinated molecule to help unlock the pigment palette of many other extinct species.
Q: Talk about the two fossilized birds that served as your study subjects. What species were they and what did you find in them?
A: The two main fossils that we analyzed in our study were the 120 million-year-old Confuciusornis sanctus, and the 110 million-year-old Gansus yumenensis. These species are both important in evolutionary terms, with C. sanctus being the first beaked bird and G. yumenensis being the most primitive member of the group that gave rise to modern birds. We were able to map elevated levels of eumelanin pigment in the neck, body and distal tail feathers of C. sanctus, but also resolve the subtle variations in tone and pigment concentrations within its wings. C. sanctus preserved both evidence of pigment chemistry but also the microscopic biological paint-pot (melanosome) that once held the pigment, so that the two were correlated for the first time. G. yumenensis, however, only preserved the distinctive copper “biomarker” indicating the presence of eumelanin pigment, given the structural (melanosome) data was long lost in the sands of time. So with G. yumenensis, without the SRS-XRF results, it would not have been possible to map the presence of the pigment.
Q: How is this approach different from the previously announced method of determining the colors of ancient creatures’ feathers?
A: Prior studies have relied upon the pigment “containers” called melanosomes (biological “paint pots”) to diagnose color. Our new results go beyond this and show that chemical remnants of pigments may survive even after the melanosome containing them has been destroyed, such as with Gansus yumenensis. The Gansus samples clearly preserve a chemical fossil, where almost all structure has been lost. More importantly the new technique allows scientists to rapidly map and quantify the chemistry of whole fossils, without having to remove samples from their precious new finds.
Q: Where can this discovery take you and other scientists in the future? Will you be able to recreate the palettes of numerous extinct animal species?
A: The synchrotron at SSRL has been used for many years to probe the innermost workings of molecules to an almost impossibly small scale. Here the team from the University of Manchester and SSRL have shown it is possible to retain the sensitivity and probing ability of the synchrotron whilst working at a much larger scale (these fossils are giants in terms of synchrotron samples). The information gleaned from the current study is way beyond anything we could have dreamed of a few years ago. The potential for this technique to gently un-pick the chemistry of long extinct species is quite breathtaking. The possibility of mapping biosynthetic pathways, enzymatic reactions and mass-transfer of elements between organic and inorganic systems through deep time offers many areas of science, not just paleontology, a cracking insight to the past. More importantly, the hindsight that the fossil record provides will undoubtedly have benefits for understanding processes on earth both today and in the future. Advances in one field are often a function of a curve ball from another.
Watch a clip from Phil Manning’s upcoming show “Jurassic C.S.I.”: