We are pleased to welcome Alison Cribb who will be delivering a seminar on: The geobiological role of benthic ecosystem engineers during key evolutionary intervals in Earth history.

Abstract:

The marine trace fossil record preserves the activity and behaviours of benthic animals over the last 560 million years. In paleoecological studies, the trace fossil record has proven particularly useful for understanding how benthic soft-bodied animals – which interacted with the sediment but do not leave robust body fossil records – have evolved and responded to environmental perturbations. Recently, the trace fossil record has been used for understanding ecosystem engineering dynamics throughout Earth history. Ecosystem engineering refers to the behaviours of animals that modify resource availability to change the habitability of an environment, and bioturbators are considered key ecosystem engineers in modern oceans. By studying the trace fossil record through the lens of ecosystem engineering, we can better understand the ways in which bioturbators have impacted benthic ecosystem functioning and the infaunal habitability of the shallow marine seafloor throughout Earth history. 

Alison Cribb will present key studies from two time periods in Earth history that represent critical transitions for life on Earth: the Ediacaran-Cambrian transition and the end-Permian mass extinction event. For both time intervals, trace fossil data have been compiled from the literature, as well as field work to characterise trace fossils in terms of their ecosystem engineering impacts. Alison has also developed sedimentary reactive-transport models informed by the trace fossil record to simulate how changes in bioturbation activity and ecosystem engineer ecology have impacted marine biogeochemical cycling through time. For both the Ediacaran-Cambrian transition and the end-Permian mass extinction, the results of these models demonstrate that while the intensity of bioturbation is an important driver of the magnitude biogeochemical changes in the seafloor, the ecology of the bioturbators and the present ecosystem engineering behaviours plays a more important role in changing the biogeochemical cycles that ultimately impact the habitability of the seafloor.

All staff and students welcome