Palaeobiology
Researchers in UCD Palaeobiology and our collaborators investigate four broad research themes:
(1) the mode of preservation of exceptionally preserved fossils (those in which the tissues that usually decay quickly after death are preserved);
(2) the skeletal taphonomy of biomineralised tissues, in particular the remains of fossil vertebrates;
(3) how study of trace fossils and ichnofabrics helps us understand the ecology of palaeoecosystems.
(4) A growing area of interest is the application of conservation palaeobiology to improve understanding of the impact of recent environmental change of anthropogenic origin on shallow marine ecosystems in the northern Atlantic.
Our studies of exceptionally preserved biotas use experimental simulation of the processes of decay and mineralisation, and a posteriori reconstructions of the taphonomy of the biotas themselves (the processes leading to their preservation). A particular area of expertise in the group is the application of non-destructive electron-beam methodologies to investigating the geochemistry of these fossils.
The ultimate goal of analyses of the skeletal taphonomy of vertebrates is to build the first comprehensive models of how the fidelity of preservation changes at various spatio-temporal scales in response to the organisms’ ecologies and the depositional and environmental context, and how this impacts on the quality of the skeletonised fossil record. A key method is the development and refinement of simple metrics that allow results from different biotas (and multiple users) to be compared directly.
Bioturbation by organisms (principally, but not always, animals) to produce trace fossils alters the physical, chemical and biological structure of sediments in ways that were highly dynamic spatially and temporally, and had significant "knock-on" effects on the structure of the biosphere; we are only beginning to understand these complex interactions and feedbacks in depth. Most of our research has been to document the assembly of complex animal communities in the aftermath of the Cambrian Explosion.
Recent publications
Doyle, E., Orr, P. and Murray, J., 2021. The earliest occurrence of the ichnogenus Psilonichnus: a new record from the Mississippian of the West of Ireland. Ichnos, 28(3), pp.208-216.
Yang, Z., Jiang, B., McNamara, M.E., Kearns, S.L., Pittman, M., Kaye, T.G., Orr, P.J., Xu, X. and Benton, M.J., 2020. Reply to: No protofeathers on pterosaurs. Nature Ecology & Evolution, 4(12), pp.1592-1593.
Slater, T.S., McNamara, M.E., Orr, P.J., Foley, T.B., Ito, S. and Wakamatsu, K., 2020. Taphonomic experiments resolve controls on the preservation of melanosomes and keratinous tissues in feathers. Palaeontology, 63(1), pp.103-115.
Van Acken, D., Tütken, T., Daly, J.S., Schmid-Röhl, A. and Orr, P.J., 2019. Rhenium‑osmium geochronology of the Toarcian Posidonia Shale, SW Germany. Palaeogeography, Palaeoclimatology, Palaeoecology, 534, p.109294.
Gebremichael, A., Orr, P.J. and Osborne, B., 2019. The impact of wetting intensity on soil CO2 emissions from a coastal grassland ecosystem. Geoderma, 343, pp.86-96.
Yang, Z., Jiang, B., McNamara, M.E., Kearns, S.L., Pittman, M., Kaye, T.G., Orr, P.J., Xu, X. and Benton, M.J., 2019. Pterosaur integumentary structures with complex feather-like branching. Nature ecology & evolution, 3(1), pp.24-30.
McNamara, M.E., Kaye, J.S., Benton, M.J., Orr, P.J., Rossi, V., Ito, S. and Wakamatsu, K., 2018. Non-integumentary melanosomes can bias reconstructions of the colours of fossil vertebrates. Nature Communications, 9(1), pp.1-9.
McNamara, M.E., Zhang, F., Kearns, S.L., Orr, P.J., Toulouse, A., Foley, T., Hone, D.W., Rogers, C.S., Benton, M.J., Johnson, D. and Xu, X., 2018. Fossilized skin reveals coevolution with feathers and metabolism in feathered dinosaurs and early birds. Nature Communications, 9(1), pp.1-7.
Gebremichael, A.W., Osborne, B. and Orr, P., 2017. Flooding-related increases in CO 2 and N 2 O emissions from a temperate coastal grassland ecosystem. Biogeosciences, 14(10), pp.2611-2626.
Orr, P.J., Adler, L.B., Beardmore, S.R., Furrer, H., McNamara, M.E., Peñalver-Mollá, E. and Redelstorff, R., 2016. “Stick ‘n’peel”: Explaining unusual patterns of disarticulation and loss of completeness in fossil vertebrates. Palaeogeography, Palaeoclimatology, Palaeoecology, 457, pp.380-388.
McNamara, M.E., Van Dongen, B.E., Lockyer, N.P., Bull, I.D. and Orr, P.J., 2016. Fossilization of melanosomes via sulfurization. Palaeontology, 59(3), pp.337-350.
McNamara, M.E., Orr, P.J., Kearns, S.L., Alcalá, L., Anadón, P. and Peñalver, E., 2016. Reconstructing carotenoid-based and structural coloration in fossil skin. Current Biology, 26(8), pp.1075-1082.
Rogers, C.S., Hone, D.W., McNamara, M.E., Zhao, Q., Orr, P.J., Kearns, S.L. and Benton, M.J., 2015. The Chinese Pompeii? death and destruction of dinosaurs in the Early Cretaceous of Lujiatun, NE China. Palaeogeography, Palaeoclimatology, Palaeoecology, 427, pp.89-99.
Redelstorff, R. and Orr, P.J., 2015. The anatomy of nonbiomineralized chordate fossils: insights from experimental decay of Xenopus laevis tadpoles. Palaios, 30(4), pp.335-351.