PhD: Worms on film: How, where and when did metazoans begin bioturbating microbial substrates?

The evolution of macroscopic bioturbation – when metazoans began burrowing into sediments – changed an essentially two-dimensional sediment-water interface into a complex, dynamic, three-dimensional environment, and is one of the fundamental developments in the history of life on Earth. However, it remains unclear how early organisms began penetrating microbially bound substrates of the Precambrian to begin producing the thoroughly burrowed and pervasively “sticky” sedimentary successions of the present-day. Moreover, where – geographically, bathymetrically, palaeoenvironmentally, sedimentologically – did this process begin?

This PhD project will unite experimental marine biology and sedimentology with geology and palaeobiology to explore these crucial questions. It will focus on interrogating the development of bioturbation in microbial dominated sedimentary successions, particularly across the Ediacaran–Cambrian transition, and the resultant biogenic sedimentology, but will be informed and guided by experimental studies of bioturbators and their impacts on microbially bound sediments. By examining the shapes and scales of sedimentary structures, the student will investigate the geological expression of biologically-mediated morphodynamics in mixed sediments, to assess how these diverge from those established for substrates devoid of such cohesion. By combining physical and biogenic sedimentological results, and comparing with experimental data, the project aims to define the geometric signatures of biota on the sedimentary record.

Funding available for UK Students and EU Students. £14,553 stipend available.
Closing date will be the 4th of August 2017, with interviews scheduled for the 16th August.