New fossilization experiments signpost the origins of organic matter in fossil soft tissues

Palaeontologists at University College Cork (UCC) have developed a new method to distinguish between remnants of the pigment melanin and other compounds in fossils. 

Dr Valentina Rossi

The soft parts of animals’ bodies (such as skin and internal organs), plus fossil plants and microbes, are rarely fossilized. When these tissues are preserved in the fossil record, they are usually altered by the effects of heat and pressure as they are buried in the Earth’s crust. Analysis of these tissues is tricky as most of the common laboratory methods that are currently available are destructive or require large amounts of sample (that are not available). As a result, it can be very difficult – if not impossible – to determine the original chemical composition of the fossil tissues.

Schematic showing a summary of the main findings of the paper. 

Now, palaeontologists at UCC have discovered a solution to this problem, by analysing samples using non-destructive Raman spectroscopy and then examining the detailed shape of peaks in the spectra using statistical analysis. The team applied their experimental model to fossil vertebrates (fish and feathers) and plants, and were able to successfully discriminate the fossils according to their original chemistry. This exciting new development will allow palaeontologists to determine the true nature of organic matter in many fossils, especially those that are older and/or more thermally altered. 

The study, published in RSC Advances, was led by UCC palaeontologists Dr Valentina Rossi and Prof. Maria McNamara. 

To find out more, visit: https://www.ucc.ie/en/mariamcnamara/

To access the scientific paper for free, click here: ht https://pubs.rsc.org/en/Content/ArticleLanding/2024/RA/D4RA04364B

Full Citation:  Rossi, V., Unitt, R., McNamara, M.E. A new non-destructive method to decipher the origin of organic matter in fossils using Raman spectroscopy.
RSC Adv., 2024,14, 26747–26759. DOI: https://doi.org/10.1039/D4RA04364B

New fossil evidence reveals hidden step in dinosaur feather evolution

Palaeontologists at University College Cork (UCC) have discovered that some feathered dinosaurs had scaly skin like reptiles today, thus shedding new light on the evolutionary transition from scales to feathers.

Dr Zixiao Yang of University College Cork, Ireland, who led the research team that discovered zoned skin development in the feathered dinosaur Psittacosaurus. Pic Ruben Tapia/UCC TV

The fossil evidence came from a new specimen of the feathered dinosaur Psittacosaurus from about 130 million years ago. Researchers discovered that Psittacosaurus, and probably other early feathered animals, had both scaly, reptile-style skin and soft, bird-like skin with feathers, in different parts of the body.

The studied Psittacosaurus specimen NJUES-10 under natural (upper half) and UV light (lower half) showing the orange-yellow fluorescence of the fossilised skin. Pic Dr Zixiao Yang

This was almost certainly for protection against abrasion, dehydration and pathogens. This way, the early feathered animals would have a good chance to survive and pass down the feather genes to their offspring and ultimately, to birds today.

The study, published today in Nature Communications, was led by UCC palaeontologists Dr Zixiao Yang and Prof. Maria McNamara. 

Scanning electron microscopy image of the fossil skin showing mineralised cell layers. Pic Dr Zixiao Yang

To find out more, visit: https://www.ucc.ie/en/mariamcnamara/news/zixiaos-discovery-on-dinosaur-skin-published-in-nature-communications.html

To access the scientific paper for free, click here: https://www.nature.com/articles/s41467-024-48400-3

Yang, Z.X., Jiang, B.Y., Xu, J.X. & McNamara, M.E. Cellular structure of dinosaur scales reveals retention of reptile-type skin during the evolutionary transition to feathers. Nature Communications 15, 4063 (2024). DOI: https://doi.org/10.1038/s41467-024-48400-3.

Mystery solved: the oldest fossil reptile from the Alps has fake skin

A 280-million-year-old fossil that has baffled researchers for decades has been shown to be, in part, a forgery following new examination of the remnants.

Dr Valentina Rossi of University College Cork, Ireland, who led the research team which discovered that a 280-million-year-old lizard fossil is, in part, a forgery. (Image credit: Zixiao Yang)

Tridentinosaurus antiquus was discovered in the Italian alps in 1931 and was thought to be an important specimen for understanding early reptile evolution.

Its body outline, appearing dark against the surrounding rock, was initially interpreted as preserved soft tissues. This led to its classification as a member of the reptile group Protorosauria.

Tridentinosaurus antiquus, which was discovered in the Italian Alps in 1931. It was long thought that the dark outline was preserved soft tissues. However researchers have now discovered that this colouring is, in fact, paint. (Image credit: Dr Valentina Rossi, UCC)

However, this new research, published in the scientific journal Palaeontology, reveals that the fossil renowned for its remarkable preservation is mostly just black paint on a carved lizard-shaped rock surface.

The discovery has led the team led by Dr Valentina Rossi of University College Cork, Ireland (UCC) to urge caution in how the fossil is used in future research.

Find out more: https://www.ucc.ie/en/mariamcnamara/news/valentinas-discovery-on-fossil-forgery-published-in-palaeontology.html

You can access the scientific article on the publisher’s website here: https://doi.org/10.1111/pala.12690

Full Citation: Rossi, V., Bernardi, M., Fornasiero, M., Nestola, F., Unitt, R., Castelli, S., Kustatscher, E., 2024. Forged soft tissues revealed in the oldest fossil reptile from the early Permian of the Alps. Palaeontology, 67, e12690. DOI: https://doi.org/10.1111/pala.12690.

New 315-million-year old fossil found in Co. Clare

Dr Eamon Doyle, Dr Joseph Botting and Dr Lucy Muir with the new fossil sponges discovered near the Cliffs of Moher in Co Clare. Photo credit:Burren and Cliffs of Moher UNESCO Global Geopark

An Irish palaeontologist has discovered a new fossil sponge species in rocks near the Cliffs of Moher.

The fossil sponge species, Cyathophycus balori, lived in an inhospitable “niche” environment where few other species could live. It was up to 50 cm tall and had a circular opening surrounded by delicate eyelash-like structures.

The upper part of the new fossil sponge shows the vertical eyelash-like structures at the very top. Photo credit: Dr. Joe Botting.

The study, published in the journal Geobios, was led by Dr Joe Botting, an international sponge expert, in collaboration with Dr Eamon Doyle, consultant geologist with the Burren and Cliffs of Moher UNESCO Geopark, who discovered the specimen.

To find out more, visit: https://www.sciencedirect.com/science/article/abs/pii/S0016699523000736

Botting, JP, Muir, LA and Doyle, E. 2023. An oversized, late-surviving reticulosan sponge from the Carboniferous of Ireland. Geobios 80, 1-13. https://doi.org/10.1016/j.geobios.2023.07.004

Ginger pigment molecules found in fossil frogs 

Illustration of the main findings reported in Slater et al., 2023 published in Nature Communications. Design by Science Graphic Design. 

Palaeontologists at University College Cork (UCC) have found the first molecular evidence of phaeomelanin, the pigment that produces ginger colouration, in the fossil record.  

The new study reports the preservation of molecular fragments of the pigment phaeomelanin in 10-million-year-old frogs, adding molecular analysis to the palaeontologists’ arsenal when reconstructing the original colours of extinct organisms. 

The study, published today in Nature Communications, was led by UCC palaeontologists Dr Tiffany Slater and Prof. Maria McNamara. 

False colour scanning electron microscopy image of zebrafinch feather showing the feather cortex (in blue) and melanosomes (melanin-rich granules, in orange). Scale bar indicates 1 µm. Pic Dr Tiffany Slater. 

To find out more, visit: https://www.ucc.ie/en/mariamcnamara/news/tiffanys-findings-on-ginger-pigments-in-fossil-record-published-in-nat-comms.html  

To access the scientific paper for free, click here: https://www.nature.com/articles/s41467-023-40570-w  

Dr Tiffany Slater and Prof Maria McNamara pictured at the School of Biological, Earth and Environmental Sciences at University College Cork. Pic Daragh Mc Sweeney/Provision. 

Slater, T.S., Ito, S., Wakamatsu, K., Zhang, F., Sjövall, P., Jarenmark, M., Lindgren, J., McNamara, M.E., 2023. Taphonomic experiments reveal authentic molecular signals for fossil melanins and verify preservation of phaeomelanin in fossils. Nature Communications 14, 5651 (2023). https://doi.org/10.1038/s41467-023-40570-w  

Ancient rivers and Ireland’s oldest fossil forest 

An international team of palaeontologists, including Emeritus Professor Ken Higgs from University College Cork, have discovered new evidence of what the first forests on Earth looked like. The researchers studied fossil plants from the Late Devonian rocks of Hook Head, Co. Wexford (about 360 million years old). The study reports the oldest log jam – a buildup of wood and logs formed during floods – plus driftwood and evidence of how river channels were stabilized by plant roots. Some fragments of driftwood even show meandering trails and burrows, indicating that they acted as a nutrient source for burrowing organisms. These interactions between plants, the sediment surface, and animals were common during the younger Carboniferous Period, but the new research shows that even the earliest forests in the Devonian Period were having a major impact on terrestrial environments.  

Fossil plant roots from Late Devonian rocks of Hook Head, Co. Wexford (ca. 360 million years old)

You can access the scientific article on the publisher’s website here: https://doi.org/10.1016/j.palaeo.2023.111579 

Yorick P. Veenma, Neil S. Davies, Kenneth T. Higgs, William J. McMahon. Biogeomorphology of Ireland's oldest fossil forest: Plant-sediment and plant-animal interactions recorded in the Late Devonian Harrylock Formation, Co. Wexford. Palaeogeography, Palaeoclimatology, Palaeoecology 621, 111579. 

https://doi.org/10.1016/j.palaeo.2023.111579.  

Dinosaur feathers reveal traces of ancient proteins  

New method reveals similarities between dinosaurs and birds  

  This paper finds evidence of proteins in 125 million-year-old feathers, which show that ancient feathers were much more like modern-day feathers than previously thought. Design by Science Graphic Design.

Palaeontologists at University College Cork (UCC) have discovered X-ray evidence of proteins in fossil feathers that sheds new light on feather evolution.

Previous studies suggested that ancient feathers had a different composition to the feathers of birds today. The new research, however, reveals that the protein composition of modern-day feathers was also present in the feathers of dinosaurs and early birds, confirming that the chemistry of feathers originated much earlier than previously thought.  

 Fossil feather 1 cm: 50-million-year-old fossil feather from Green River, USA, which was analysed as part of the study.  

The research, published today in Nature Ecology and Evolution, was led by palaeontologists Dr Tiffany Slater and Prof. Maria McNamara of UCC’s School of Biological, Earth, and Environmental Sciences.  

 Dr Tiffany Slater and Prof. Maria McNamara pictured at the School of Biological, Earth and Environmental Sciences at University College Cork. Pic Daragh Mc Sweeney/Provision.

Find out more: https://www.ucc.ie/en/mariamcnamara/news/tiffany-has-new-paper-on-fossil-feather-proteins-in-nature-ecology-and-evolution.html  

The scientific article is provided on the journal website here:  

Slater, T.S., Edwards, N.P., Webb, S.M., Zhang, F., McNamara, M.E., 2023. Preservation of corneous β-proteins in Mesozoic feathers. Nature Ecology and Evolution.  https://doi.org/10.1038/s41559-023-02177-8  

To request a copy of the scientific article, please email tiffany.slater@ucc.ie or maria.mcnamara@ucc.ie.  

360-million-year-old Irish fossils provides oldest evidence of plant self-defence in wood 

In April this year, an international team of scientists, co-led by Dr Carla J. Harper, Assistant Professor in Botany in the School of Natural Sciences at Trinity College Dublin, discovered the oldest evidence of plant self-defence in wood in a 360-million-year-old fossil from south-eastern Ireland.  

Microscopic observation of a section of Devonian fossil wood containing tyloses and detail of an area showing several tyloses (arrows) produced by parenchyma cells (P) inside a conductor cell (C); scale: 0.05 mm (50 µm). Photos: A-L Decombeix.

Plants can protect their wood from infection and water loss by forming special structures called “tyloses”. These prevent bacterial and fungal pathogens from getting into the heartwood of living trees and damaging it. The palaeontologists discovered that very early woody plants from the Hook Head Peninsula area, Co. Wexford, Ireland, show evidence of such defences. The fossil plants lived during the Late Devonian period, 360 million years ago. These fossil plants formed the first primeval forests and were the first plants to resemble modern-day trees, with a woody trunk, branches, and complex roots – and they were capable of producing tyloses to protect from microbial attack. 

You can read the scientific article on the publisher’s website here: https://www.nature.com/articles/s41477-023-01394-0  

To read more, see: https://www.tcd.ie/news_events/articles/2023/360-million-year-old-irish-fossil-provides-oldest-evidence-of-plant-self-defence-in-wood/  

The origin of colour patterns in fossil insects 

Fossil orthopteran from the Jurassic Yanliao biota of NE China, showing colour patterns on its wings. Credit: Shengyu Wang. 

Research at UCC has resolved a long-standing question about colour patterns in fossil insects, revealing that they reflect the original colour patterns in life. The research was led by Dr Shengyu Wang, who completed part of the work on the paper during a research visit to UCC, with Prof. Maria McNamara of the UCC Palaeontology Group. The palaeontologists did thermal maturation experiments on modern insects, in order to study how their colour patterns are degraded by the effects of heating. The results showed that during progressive heating, colour patterns are initially lost as cuticles turn black, but then reappear at higher temperatures. This happens because regions of the cuticle that are rich in melanin persist but cuticle regions with little or no melanin preferentially degrade. The scientists also found that these changes happen at different temperatures, for different insect species: the thicker the cuticle, the higher the temperature these changes happen at. Therefore, when studying fossil insect biotas, the absence of colour patterns in certain species may be an artefact of fossilization. 

Shengyu Wang

You can access the scientific article for free here: 

Wang, S., McNamara, M.E., Wang, B., Hui, H., Jiang, B., 2023. The origins of colour patterns in fossil insects revealed by maturation experiments. Proceedings B, 290, 20231333.  

DOI: https://doi.org/10.1098/rspb.2023.1333