Congratulations Dr Rossi!

Dr Valentina Rossi successfully defended her PhD thesis last week. Big congratulations to Dr Rossi on her great achievements!

New paper in Scientific Reports

Spectacular X-ray maps reveal internal organs of ancient beasts

Micromelerpeton credneri

A new study uses sophisticated particle accelerator X-ray maps to reveal the internal anatomy of fossils up to 280 millions of years old.

The chemical information is locked up in fossilized melanosomes – microscopic granules of melanin. The new results show that despite the damaging effects of the fossilization process, melanosomes in many fossil vertebrates retain tissue-specific signals, allowing internal anatomy to be reconstructed.

The study was led by University College Cork (UCC) palaeontologists Valentina Rossi and her supervisor Dr Maria McNamara in collaboration with Dr Samuel Webb from SLAC National Accelerator Laboratory, USA.

The team used cutting-edge synchrotron techniques to analyse the chemistry of the fossil melanosomes using powerful X-rays.

The team studied the chemistry of preserved melanosomes in 21 fossils from localities around the world, including Europe and China. Some of the remarkable details evident in the X-ray maps include the different chemistries of the gills, eyespots, skin, and internal organs such as the liver and kidneys.

“We can still discern different internal tissues using melanosome chemistry in many fossils considered relatively young – 50 million years old or younger. What’s really remarkable is that some very ancient fossils – older than the dinosaurs – can also show good chemical preservation”, said Ms Rossi. In fossils from many other localities, traces of original melanosome chemistry have been destroyed.

Palaeobatrachus diluvianus

Senior author Dr McNamara said, “This new study emphasises the fact that fossil melanosomes have the potential to make much broader contributions to evolutionary studies than previously thought. Ten years ago, palaeontologists were using melanosomes to estimate the colours of ancient creatures. Now we know that fossil melanosomes can track changes in physiology, help discriminate between different species, and reveal internal anatomy. What next?”

The study is published today in the journal Scientific Reports.

Rossi, V., Webb, S.M., McNamara, M.E., 2020. Hierarchical biota-level and taxonomic controls on the chemistry of fossil melanosomes revealed using synchrotron X-ray fluorescence. Scientific Reports10, 8970. DOI:

Daniel awarded a grant!

Daniel has just been awarded Postgraduate Research Grant by the International Association of Sedimentologists (IAS) for a project entitled “Sedimentological controls on the taphonomy of the Eocene Geiseltal Konservat-Lagerstätte, Germany”.

Well done Daniel!

(fossil specimen shown is GMH CeII 4949-1930 from the collections of the Geiseltal Museum, Halle (Saale), Germany)

Valentina awarded a grant!

Valentina has just been awarded a grant (Borsa di studio SPI 2020) from the Società Paleontologica Italiana! She will be studying the fossil Mene rhombea from “La Pesciara” Bolca Biota in Italy.

Well done Valentina!


New paper in Biology Letters

Study finds brilliant green-blue colours in 13,000-year old fossil insects

Vivid colours produced by photonic diamonds

University College Cork (UCC) scientists have discovered 13,000-year-old fossil insects with brilliant green-blue colours produced by microscopic photonic ‘diamonds’.

These tiny structures produce the brightest and purest colours in nature and are used by insects today to produce striking visual signals. The evolution of photonic diamonds, however, is poorly understood.

Top: Fossil scales from 13,000-year-old weevils preserving bright blue, green and yellow hues. Bottom: Electron microscope images reveal the microscopic photonic ‘diamond’ structure responsible for producing these colours, which are believed to have been used for camouflage. Image credits: Luke McDonald and Maria McNamara (UCC).

Remarkably, the fossil insects preserve ancient photonic diamonds within scales on their outer surface. Unlike many of today’s insects, which are thought to use photonic diamonds for mating displays or displays of fitness, the green hues of the fossil weevils probably functioned as camouflage.

The fossil insects examined were from ancient lake sediments from Lobsigensee in Switzerland. The study was led by UCC palaeobiologists Drs Luke McDonald and Maria McNamara in collaboration with applied physicist Dr Vinod Saranathan, an expert in biological photonic systems, from YaleNUS College in Singapore.

Study leader Dr McDonald said, “This is only the second time that 3D photonic crystals have been reported from the fossil record. We identified the microscopic structures in the fossil scales using powerful electron microscopes. The photonic ‘diamonds’ in the fossils interact with wavelengths of light to produce vivid colours.”

Senior author Dr McNamara said, “The fossil record is potentially a treasure trove of information on the evolution of these structures, but it’s largely an untapped resource. More work on fossils will help us understand how these incredibly complex tissue structures evolved and how their functions may have changed through deep time.”

Artist’s impression of the weevil.

Dr Saranathan, who structural and optical analyses using particle accelerator X-rays and modelling, added, “It is very interesting to discover that insects first seem to evolve complex 3D nanoscale architectures in order to escape predators by blending in with their background (usually brown or green). Only later do these colours diverge for other uses such as signalling potential mates or as a warning to predators that the insect is not worth eating.”

The study is published today in the journal Biology Letters.

McDonald, L.T., Narayanan, S., Sandy, A., Saranathan, V., McNamara, M.E., 2020. Brilliant angle-independent structural colours preserved in weevil scales from the Swiss Pleistocene. Biology Letters, 16, 20200063. DOI:

To arrrange interviews contact Maria McNamara directly: 021 7434738 (home) /

See below for news items on the study:

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