Maria’ speaks to Derek Mooney, host of Mooney Goes Wild on RTÉ Radio, about feather evolution!
https://www.rte.ie/radio/utils/radioplayer/rteradioweb.html#!rii=b9%5F21413699%5F82%5F13%2D08%2D2018%5F (Maria’s interview begins at 05:48!)
(image: black aggregates of melanosomes in a histological section of extant frog liver)
UCC palaeontologists make new discovery forcing rethink on colours of fossil birds, reptiles and dinosaurs
A UCC-led discovery of new sources of the pigment melanin will force scientists to rethink how they reconstruct the colour of fossil birds, reptiles and dinosaurs.
Many recent studies of fossil colour have assumed fossilized granules of melanin – melanosomes – come from the skin. But new evidence shows that other tissues – such as the liver, lungs, and spleen – can also contain melanosomes, suggesting that fossil melanosomes may not provide information on fossil colour.
The study, published today in the journal Nature Communications, is led by UCC’s Dr Maria McNamara in collaboration with her PhD student Valentina Rossi, Dr Patrick Orr from UCD, and an international team of palaeontologists from the UK and Japan.
‘It’s absolutely critical that we understand the origins of melanosomes in fossils if we want to produce accurate reconstructions of the colours of ancient animals,’ said Dr McNamara.
The team studied internal tissues in modern frogs with powerful microscopes and chemical techniques to show that internal melanosomes are highly abundant.
“This means that these internal melanosomes could make up the majority of the melanosomes preserved in some fossils,” said collaborator Prof. Mike Benton at the University of Bristol.
The team also used decay experiments and analysed fossils to show that the internal melanosomes can leak into other body parts during the fossilization process, “like snowflakes inside a snow globe”, said Dr Orr.
There is a way, however, to tell the difference between melanosomes from internal organs and the skin. “The size and shape of skin melanosomes is usually distinct from those in internal organs’, said Dr McNamara. ‘This will allow us to produce more accurate reconstructions of the original colours of ancient vertebrates.”
The paper is published today in Nature Communications: https://www.nature.com/articles/s41467-018-05148-x
See below for some news items on the study:
The impact of organic matter on heavy metal bioavailability in urban soils: experimental and field-based approaches
Heavy metal (HM) contamination in urban soils is a major global geohazard, but data on this issue in Ireland is lacking, particularly the extent to which the amount and type of soil organic matter affects the bioavailability and chemical state of HM. The proposed research will resolve these issues using a powerful dual approach combining the first systematic survey of urban soils in southern Ireland, focussing on soils in recreational areas, and innovative laboratory experiments exploring the impact of different sources of organic matter on heavy metal solubility, oxidation state and local chemical environment. The study will provide baseline data on the extent and toxicity of HM contamination in Irish urban recreational soils, guiding planning and bioremediation, and will serve as a platform for developing research capacity on the fate of HM in the geosphere. Diverse dissemination activities will ensure visibility of the research amongst academics, policymakers and the public.
The project is funded under the iCRAG – GSI Environmental Geosciences PhD Programme and is supported by Science Foundation Ireland (SFI) and the GSI.
Projects are fully funded for four years with a stipend of €18,500 per annum plus fees for EU applicants.
Project start date: 3rd September 2018
Application deadline: 1 pm Friday 22 June 2018
How to apply
UCC palaeontologists Maria McNamara and her postdoc Chris Rogers have discovered 125-million-year old dandruff preserved amongst the plumage of feathered dinosaurs and early birds.
Just like human dandruff, the fossil dandruff is made of tough cells called corneocytes, which in life are dry and full of the protein keratin.
The study, published today in the journal Nature Communications, is led by Maria and features other researchers from UCC (Dr Andre Toulouse and Ms Tara Foley from the UCC Dept. of Anatomy and Neuroscience), Dr Patrick Orr from UCD and researchers from the UK and China.
The team studied the fossil cells, and dandruff from modern birds, with powerful electron microscopes. ‘The fossil cells are preserved with incredible detail – right down to the level of nanoscale keratin fibrils’ said Dr McNamara. ‘What’s remarkable is that the fossil dandruff is almost identical to that in modern birds – even the spiral twisting of individual fibres is still visible.’
Modern birds have very fatty corneocytes with loosely packed keratin, which allows them to cool down quickly when they are flying for long periods. The corneocytes in the fossil dinosaurs and birds, however, were packed with keratin, suggesting that the fossils didn’t get as warm as modern birds, presumably because they couldn’t fly at all or for as long periods.
See below for several news articles related to the findings:
Maria’s research was also mentioned on a recent episode of “Have I Got A Bit More News For You”!
Fossil study sheds light on ancient butterfly wing colours!
New research by scientists at UCC has revealed the wing colours of some of the oldest ancestors of modern butterflies and moths.
The 180 million-year-old fossils, preserved in rocks and amber, would have had bronze to golden colours produced by microscopic ridges and grooves on the surface of their wing scales. These fossils extend the evidence for light-scattering structures in insects by more than 130 million years.
UCC palaeobiologists Drs Maria McNamara and Luke McDonald reconstructed the colours using powerful electron microscopes and optical modelling. Similar ridges and grooves are still seen in modern primitive moths.
Dr McDonald said, “Insects have evolved an amazing diversity range of photonic nanostructures that can produce iridescence, metallic colours, and other eye‑catching effects that play a vital role in visual signalling.”
Dr McNamara said “Remarkably, these fossils are among the oldest known representatives of butterflies and moths. We didn’t expect to find wing scales preserved, let alone microscopic structures that produce colour. This tells us that colour was an important driving force in shaping the evolution of wings even in the earliest ancestors of butterflies and moths”.
The results of the study (“Fossil scales illuminate the early evolution of lepidopterans and structural colors”) are published in the journal Science Advances, and are available here!
See below for several news articles related to the findings:
Dr Maria McNamara spoke to CRY104FM about her new research: it revealed how the history of life can be distorted by the ways animals decompose and lose body parts as they decay – and the ways in which decayed bodies ultimately become fossilised. The new paper (“Experimental Analysis of Soft-Tissue Fossilization: Opening the Black Box“) is from a group of palaeontologists from the UK and Ireland, led by the University of Leicester, and is published in the journal Palaeontology.
Palaeontologists investigate the macabre science behind how animals decay and fossilise
New research has revealed how the history of life can be distorted by the ways animals decompose and lose body parts as they decay – and the ways in which decayed bodies ultimately become fossilised.
In a new study (‘Experimental Analysis of Soft-Tissue Fossilization: Opening the Black Box’) published in the journal Palaeontology, a group of palaeontologists from the UK and Ireland, led by the University of Leicester, have followed a macabre, and nasally-challenging road to knowledge – watching carefully as animal carcasses decompose in order to better understand the process.
Like on-screen zombies in popular TV programmes such as The Walking Dead that gradually deteriorate through time, fossils preserve only incomplete remains of the living body.
A key part of palaeontological research involves reconstructing long-extinct creatures to understand what they were like when they were alive. This knowledge allows us to answer fundamental questions – how did they move and interact with their environment? How did they feed and reproduce? Which of today’s organisms are they most like and most closely related to?
Understanding how much of a fossil is missing, and what has been changed by decay and fossilisation, helps to create a more accurate picture of ancient animals and ecosystems. This is particularly important for things lacking hard skeletons and shells – including crucial fossil evidence of early animal life on Earth.
“As soon as an organism dies, it starts to decay, and this process of decomposition inevitably involves changes in how features or body parts look: they may collapse, alter their shape or position; all too soon they liquefy and are eaten by bacteria until nothing remains,” says Professor Sarah Gabbott from the University of Leicester’s School of Geography, Geology and the Environment.
Professor Mark Purnell, lead author of the study adds: “The more a body deteriorates over time, the more body-parts are missing – rather like modern representations of zombies in Game of Thrones and The Walking Dead.
Zombie fossil? Artist’s impression of an undead T. rex. The missing parts are the result of degradation of the body after death. For almost every organism that has ever lived, degradation continued until nothing was left. Fossils are rare, and occur when other processes, such as mineral formation, preserve body parts and prevent them from being lost to decay. Scientific reconstructions of long-extinct organisms are at risk of inadvertently creating incomplete ‘zombie fossils’ if the processes of decay and preservation are not taken into account.
“One consequence of this decay is that palaeontologists have to work with incomplete fossils. Some of the features that are present don’t look anything like they did when the animal was alive, and many features are missing completely. The trick is to be able to recognise partially-decomposed features, and where body parts have rotted away completely.”
The approach used in the UK-Irish collaboration involves ‘laboratory decay experiments’: keeping careful records of every body part as it decays away.
The results of rotting a whole range of dead animals, from hagfish and lampreys (primitive eel-like creatures) to insects and various worms, show that carefully designed experiments provide unique insights into the processes of decomposition and fossilisation.
In the new paper they highlight the importance of understanding how a fossil is formed before trying to reconstruct it – how the processes of decay that lead to loss of body parts interact with the processes that cause them to become preserved and fossilised.
Dr Maria McNamara, collaborator in the study, adds: “If we understand this we are better able to avoid producing incomplete restorations of animals with crucial parts missing or decayed, and to recognize and be aware of the gaps in our knowledge.”
Maria also did an interview with BBC4 Radio this morning – the interview is available here!
BEES palaeontologist Dr Maria McNamara has been awarded the Paleonturology Award 2017 in recognition of her 2016 paper ‘Fossilization of melanosomes via sulfurization’ published in the journal Palaeontology. The paper was co-authored by Drs Bart van Dongen and Nick Lockyer (University of Manchester), Dr Ian Bull (University of Bristol) and Dr Paddy Orr (University College Dublin).
The award is made by the Fundacion Conjunto Palaeontologico de Teruel – Dinopolis each year. It recognizes outstanding palaeontological research and is given to what is considered the best paper in any field of palaeontology (of those selected for consideration) in the preceding year. The award comes with a cash prize of €4,500.
The award also aims to promote this research to schoolchildren, and the recipient of the award is expected to prepare a popular version of the winning article for dissemination amongst secondary school students.
Maria (centre) and some of her team at UCC
The news article (in Spanish!) can be accessed here: