My research uses fossil and extant data from multiple spatiotemporal scales to understand ecosystem structure and interactions, the autecology and life history of the organisms within these systems, how they responded to environmental perturbations, and how these factors influenced macroevolutionary and biodiversity patterns in deep time contexts. I use a combination of research methods, both field- and lab-based, including geochemical analyses, osteohistology, multi-variate statistics and quantitative biodiversity metrics, sedimentology, morphometrics and taxonomy, and modern analogue ecological surveys.

1. Cullen, T.M., Longstaffe, F.J., Wortmann, U.G., Huang, L. and Evans, D.C., 2023. Anomalous ¹³C enrichment in Mesozoic vertebrate enamel reflects environmental conditions in a “vanished world” and not a unique dietary physiology. Paleobiology, pp.1-15.
2. Cullen, T.M., Zhang, S., Spencer, J. and Cousens, B., 2022. Sr‐O‐C isotope signatures reveal herbivore niche‐partitioning in a Cretaceous ecosystem. Palaeontology, 65(2), p.e12591
3. Cullen, T.M., Longstaffe, F.J., Wortmann, U.G., Huang, L., Fanti, F., Goodwin, M.B., Ryan, M.J. and Evans, D.C., 2020. Large-scale stable isotope characterization of a Late Cretaceous dinosaur-dominated ecosystem. Geology, 48(6), pp.546-551.
4. Cullen, T.M., Canale, J.I., Apesteguía, S., Smith, N.D., Hu, D. and Makovicky, P.J., 2020. Osteohistological analyses reveal diverse strategies of theropod dinosaur body-size evolution. Proceedings of the Royal Society B, 287(1939), p.20202258.
5. Cullen, T.M. and Evans, D.C., 2016. Palaeoenvironmental drivers of vertebrate community composition in the Belly River Group (Campanian) of Alberta, Canada, with implications for dinosaur biogeography. BMC Ecology, 16(1), pp.1-35.