Overview

Project Highlights:

  • Deciphering the early evolutionary history of the cerapodan dinosaurs;
  • Re-examining specimens in the light of new data and with state-of-the-art quantitative techniques;
  • Exploring implications for dinosaur biogeography and diversity through time.
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Overview:

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.

Figure 1: A reconstruction of the cerapodan ornithischian Hypsilophodon from the Early Cretaceous of the Isle of Wight. Reconstruction by Arthur Weasley; CC BY 2.5.

Methodology

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.

Training and Skills

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.

Timeline

Year 1: Training in vertebrate anatomy, taxonomy, and phylogenetics. Data collection in the NHM and USA. Work on anatomical descriptions and taxonomic revisions. Histological sampling. Conferences: SVPCA (UK), EAVP (Europe).

Year 2: Additional overseas data collection, particularly in China. Completion of anatomical descriptions and taxonomic revisions. Interpretation of histological data. Submission of first publications. Conferences: SVPCA (UK), EAVP (Europe).  

Year 3: Development and analysis of phylogenetic dataset. Quantitative analyses of biogeography and diversity through time. Ongoing publication of results. Write up and submision of thesis. Conferences: SVPCA (UK), SVP (USA).    

Partners and collaboration (including CASE)

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.

 

Further Details

Please contact susannah.maidment@nhm.ac.uk for more information.