PhD: Evolution and phylogenetic relationships of the early cerapodan dinosaurs

Cerapodans are a major group of herbivorous bipedal and quadrupedal ornithischian dinosaurs that dominated the terrestrial herbivorous niche during the Cretaceous. Early in their evolutionary history they split into two major groups, the ornithopods (duck-billed dinosaurs and their relatives) and the marginocephalians (horned and frilled dinosaurs and dome-headed dinosaurs). Subsequent to the split both groups radiated and developed complex chewing mechanisms and social structures that allowed them to achieve high diversity and abundance, and their fossils are well-known from outstanding material. However, early representatives of Cerapoda are known from much more fragmentary remains, and this has hindered our understanding of their taxonomy, relationships, and evolution. In particular, the ontogenetic status of many of the early cerapodans is unknown, and their fragmentary fossil record means that character transitions at the base of Cerapoda remain unclear. This has limited our interpretation of the evolution of mega-herbivory and quadrupedality in these dinosaurs. Competing phylogenetic hypotheses indicate radically different evolutionary relationships for early cerapodans, and it remains particularly unclear which taxa are included within Ornithopoda.

The aim of this project is to conduct a comprehensive anatomical and systematic evaluation of all basal cerapodans and resolve phylogenetic uncertainties, providing a robust evolutionary tree. This tree will then be used to investigate the evolutionary history of Cerapoda with a focus on palaeobiogeography, diversity through time, and the timings of major divergences and radiations. Key research aims include: (1) resolving the taxonomy of key basal cerapodans, with a particular focus on North American Late Jurassic taxa; (2) examining the ontogenetic status and population ecology in a large sample of Early Cretaceous British taxa; (3) determining the phylogenetic position of basal cerapodans relative to the divergence of Ornithopoda and Marginocephalia; (4) using the resulting hypothesis to explore biogeographic and diversity patterns through time.
The student will be based at the Natural History Museum (NHM), making use of the extensive dinosaur collections, including key taxa for this project. They will supplement this data by visiting important museum collections worldwide, particularly in the USA and China. Specimens will be histologically sampled to determine their ontogenetic status. The student will build a comparative database of photos, measurements and anatomical data, and will use this to carry out taxonomic revisions, anatomical descriptions, and score characters for the most comprehensive phylogenetic analysis carried out to date on these taxa. The phylogenetic dataset will be analysed using parsimony and Bayesian approaches to elucidate evolutionary relationships at the base of Cerapoda. Quantitative analyses of biogeography and diversity will be conducted by combining the phylogenetic hypotheses with stratigraphic and geographic data from the Paleobiology Database (www.paleobiodb.org) using appropriate packages within the programming environment R.

Funding for this project is through the CENTA NERC DTP (http://centa.org.uk/), and the awarding institution will be the University of Birmingham. Funding is available for UK and EU students; non-EU applicants are not eligible to apply. The supervisory team will comprise Dr Susannah Maidment (NHM), Professor Richard Butler (Birmingham) and Professor Paul Barrett (NHM). The supervisors are leading experts in ornithischian dinosaur anatomy, taxonomy and systematics, and have a wide international network of collaborators that will facilitate access to fossil material worldwide.

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes. Comprehensive project-specific training will be provided and will include vertebrate anatomy, taxonomy, how to describe and photograph fossil specimens, building and using comparative databases, using various quantitative approaches to build phylogenies and test evolutionary trends over time (including coding in R), and international scientific collaborations. The NHM provides unparalleled opportunities for public outreach and engagement and the student will be encouraged and trained to participate in these. Opportunities may also be available for the student to gain skills in finding and collecting fossils in the field, through the supervisors’ active international fieldwork programmes.