PhD: The biogeographical history of Mesozoic dinosaurs

Dinosaurs first appeared approximately 230 million years ago (Ma) and rapidly became globally distributed. Although the continents were still joined early in dinosaurian evolutionary history, Pangaean fragmentation led to their increasing separation. Determining the impact of Pangaean fragmentation on the distribution of life, in terms of the geographic separation and dispersal of species, is one of the central goals of biogeography, but fierce debate and uncertainty plagues this field. How did this fragmentation constrain dispersal routes, especially given that not all dinosaur groups were cosmopolitan? Were there palaeogeographic and/or climatic/environmental barriers to dispersal, and how did these shape the distribution of dinosaur diversity? This project takes advantage of recently developed, cutting-edge analytical methods that have not previously been applied to dinosaurs as a whole. The student will build a time-calibrated informal supertree of Mesozoic dinosaurs to analyse their biogeographical history in a phylogenetic context, using both likelihood and network analysis approaches, and will also use occurrence data to analyse biogeographic patterns in a Bayesian framework. Sampling and palaeogeographic/environmental barriers/filters to dispersal will also be incorporated into the models, factors that have largely been ignored in previous studies. These analyses will enable the student to evaluate the relative roles of vicariance and dispersal on the distribution of dinosaurs through time, and to test whether continental fragmentation correlates with speciation and/or extinction rates. Furthermore, these approaches are applicable to any group with an evolutionary tree, including extant taxa, opening up a wide array of future research directions.

Button et al. 2017. Mass extinctions drove increased global faunal cosmopolitanism on the supercontinent Pangaea. Nature Communications 8: 733 [method only].

Dunhill et al. 2016. Dinosaur biogeographical structure and Mesozoic continental fragmentation: a network-based approach. Journal of Biogeography 43: 1691–1704.

Poropat et al. 2016. New Australian sauropods shed light on Cretaceous dinosaur palaeobiogeography. Scientific Reports 6: 34467.

Silvestro et al. 2016. Fossil biogeography: a new model to infer dispersal, extinction and sampling from palaeontological data. Philosophical Transactions of the Royal Society B 371: 20150225 [method only].