About the Authors

David M. Martill

david.martill@port.ac.uk

Affiliation School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth, United Kingdom

Steven U. Vidovic

Affiliation School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth, United Kingdom

Cindy Howells

Affiliation Department of Natural Sciences, Amgueddfa Cymru - National Museum Wales, Cardiff, United Kingdom

John R. Nudds

Affiliation School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: DMM SUV JN CH. Performed the experiments: DMM SUV JN CH. Analyzed the data: DMM SUV JN CH. Contributed reagents/materials/analysis tools: DMM SUV JN CH. Wrote the paper: DMM SUV JN CH. Cladistic analysis: SUV DMM. Stratigraphic analysis: DMM JN CH.