Wednesday 2 September, 2.30pm BST. Over Zoom (Details sent to registered attendees) Getting inside the heads of early vertebrates Animals with backbones (vertebrates) have an evolutionary history of nearly half a billion years, with fossils instrumental in understanding how the group became so hugely successful. Jawed bony fishes account for 99% of living vertebrate species, and over half of these are ray-finned fishes: staples of the aquarium and fishmonger, encompassing everything from goldfish to seahorses to cod. However, the double barriers of geological time and fossil preservation has led to a poor understanding of the early history and evolution of ray-fins. Many of the major innovations that drove ray-fins to be so diverse are tied up in the braincase, a bony box that sits within the head and houses the brain and sensory organs. Traditionally, these internal structures would be accessed by gradually grinding the fossil away into dust, recording the morphology through a series of drawings. By using x-ray tomography (CT scanning), it is possible to ‘virtually’ cut through the specimens without damaging the fossil. CT scanning works in exactly the same way as getting an x-ray or CAT scan at a hospital: different materials in the fossil absorb differing amounts of x-rays. This can be used to build up a picture of the fossil's internal anatomy, opening a window into the evolution of the skull and brain. Comparing these structures between key living and extinct ray-fins allows for major events to be put into context, shedding new light on innovations and evolutionary relationships. These findings also provide insight into the explosive diversification of ray-finned fishes some 350 million years ago. Sam Giles - University of Birmingham ‘The GeolSoc public lecture series represent a way to communicate my research to a broader audience. An online presentation will hopefully make it even broader still!’ Sam is a Royal Society research fellow at the University of Birmingham, prior to this she completed her MSci in Geology at the University of Bristol in 2011 and a D.Phil in Palaeobiology at the University of Oxford in 2015. She then spent two years as a Junior Research Fellow at Christ Church, Oxford. Sam's main research interests are in the relationships and morphology of bony vertebrates. She uses non-destructive x-ray imaging (CT scanning) to unlock the external and internal anatomy of living and fossil vertebrates. She focuses on the early history of bony fishes, which account for 99% of all living vertebrates. Her work provides insight into the origins and evolutionary success of different vertebrate groups. Reading list: - Friedman, M., Pierce, S. E., Coates, M. I., Giles S. 2019. Feeding structures in the ray-finned fish Eurynotus crenatus (Actinopterygii: Eurynotiformes): implications for trophic diversification among Carboniferous actinopterygians. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, https://doi.org/10.1017/S1755691018000816 - Giles, S., Xu, G.-H., Near, T. J., Friedman, M. 2017. Early members of ‘living fossil’ lineage imply later origin of modern ray-finned fishes. Nature, https://doi.org/10.1038/nature23654 - Lu, J., Giles, S., Friedman, M., Den Blaauwen, J. L., Zhu, M. 2016. The oldest actinopterygian highlights the cryptic early history of the hyperdiverse ray-finned fishes. Current Biology, http://dx.doi.org/10.1016/j.cub.2016.04.045. - Giles, S., Darras, L., Clément, G., Blieck, A., Friedman, M. 2015. An exceptionally preserved Late Devonian actinopterygian provides a new model for primitive cranial anatomy in ray-finned fishes. Proceedings of the Royal Society B, https://doi.org/10.1098/rspb.2015.1485 Popular papers from the GSL Lyell Collection: -Re-evaluation of the Permian macrofossils from the Parnaíba Basin: biostratigraphic, palaeoenvironmental and palaeogeographical implications https://sp.lyellcollection.org/content/472/1/223 -A lower Carboniferous (Visean) tetrapod trackway represents the earliest record of an edopoid amphibian from the UK https://jgs.lyellcollection.org/content/177/2/276 Finally thank you for joining in with this Public Lecture. We have more upcoming virtual events that we think maybe of interest to you: -Geo Poetry – 1 October. Register here -GSL Public Lecture - Lost in Translation: Why Talking About Geoscience is so difficult with Hazel Gibson – 12 October. Register here -Mineral Resource Estimations: Recent Advances and Current Best Practice – 19 October. Register here -GSL Public Lecture: Engaging geoscience for diplomacy – understanding Paektu volcano in North Korea with James Hammond – 9 November. Register here -GSL Public Lecture: ‘Reading the ground’ to reduce hazards and risks in engineering projects with Andrew Hart – 3 December. Register here .