Overview

Project Highlights:

  • Join a world-class team of scientists working to understand the links between extreme climate events and ecosystem dynamics
  • Constrain the dominant patterns, responses and driver(s) of marine ecosystem change
  • Learn a diverse range of key statistical, palaeobiological and geochemical techniques to investigate controls on past life and relevance to modern communities

Overview:

The Palaeocene-Eocene Thermal Maximum (PETM) ~56 million years ago, is the largest of a series of abrupt global warming events known from the Cenozoic. During this event, the oceans rapidly warmed by >5 °C and became more acidic, and the world became wetter and stormier with profound consequences for life on land and in the oceans. The PETM was driven by the injection of isotopically light carbon (e.g., from volcanoes or methane hydrates) into the atmosphere, and many of the associated environmental changes are similar to those occurring today. Therefore, the PETM is often considered the best geological analogue to help us understand anthropogenic environmental change and its impacts. However, whilst a large number of studies have investigated biotic and environmental change at the PETM, these have primarily focussed on individual sites or single organismal groups, preventing an understanding of both the spatial patterns of change (e.g., development of tropical exclusion zones) and ecosystem functioning before, during and after abrupt environmental change, and the relative role of abiotic drivers on these changes.

The student will address this deficit by generating/compiling datasets to quantify marine ecosystem change globally. These data will be integrated with extensive palaeoenvironmental datasets, in many cases from the same sites. Key questions that will be addressed include:

  • was there a change in ecosystem function during the PETM?
  • was temperature the dominant driver of marine ecosystem change?
  • How do organisms with different ecologies and habitat preferences respond to the same environmental drivers?
Figure 1: PETM sea surface temperature (top) and selected microfossil groups – foraminifera, dinoflagellates and fish teeth (left to right) - that show evidence of pronounced community change at the PETM. Images from: Dunkley Jones et al. (2013); Pearson et al. (2006); Appy Sluijs; Sigbert et al. (2017).

Methodology

The student will collate existing species abundance and diversity datasets alongside co-occurring environmental datasets spanning the PETM. In the first instance, marine benthos and nekton will be targeted and supplemented by new data collection where significant gaps are identified (e.g., ichnofossils, fish, sharks, corals). This new data collection will utilise NHM and IODP materials, including new material recovered by Edgar during IODP Expedition 369 in the SW Indian Ocean and may involve fieldwork. These data will be supplemented by morphological data as appropriate (e.g., body size). The resulting data compilation will be used to quantity changes in the ecological structure and function of marine communities across the PETM.

Data will be compared with multiple geochemical and sedimentological proxies detailing marine environmental change, including bottom water temperature, water column stratification, carbon and nutrient cycling, and oxygenation. These will be used to assess the relative influence of abiotic factors on biotic change.

Training and Skills

The student will gain experience in data synthesis, creating new and using existing databases, taxonomic identification of fossil marine organisms and in applying geochemical, sedimentological and palaeoecological techniques to address key questions in earth system sciences. The student will develop skills in multivariate statistical techniques, graphing and mapping in the free R environment. Opportunities for travel to visit museum collections, core repositories or fieldwork are possible, and relevant training will be provided. These skills are highly transferable within academia and industry, and will enable the student to specialise as a palaeontologist or palaeoclimatologist.

Timeline

Year 1: Complete literature review and initial data compilation of marine benthos and/or nekton as well as corresponding environmental records across the PETM. Identify key gaps in existing organismal or spatial coverage and fill where possible. Presentation of initial results at Palaeontological Association annual meeting in 2019/2020, e.g., Valencia, Spain. You will have regular meetings with your co-supervisor at the NHM, London throughout the PhD.

Year 2: Continued data collection, interpretation, and develop manuscript 1. Presentation of results at large international meeting in 2020/2021 such as the Geological Society of America (GSA) annual meeting in Canada and a UK based meeting, e.g., Palaeontological Association.

Year 3: Complete outstanding data collection, analyses, and interpretation. Prepare remaining manuscripts and thesis write-up. Presentation of final results at European Geosciences Union Meeting in Vienna or GSA, and Palaeontological Association annual meeting.

Partners and collaboration (including CASE)

This project was developed in collaboration with the Natural History Museum. It brings together expertise from different areas to maximise the value of existing datasets to tackle pressing questions relating to the impact of abrupt environmental change on marine communities. Each supervisor brings a complimentary skill set: Edgar is a Cenozoic microfossil specialist and palaeoceanographer specialising in abrupt ancient global warming events; Twitchett specialises in the early Mesozoic warming-related mass extinction events and effects on marine ecosystems; Butler is a vertebrate palaeontologist with relevant expertise in building and using palaeontological databases (especially the Paleobiology Database) and quantitative analysis of macroevolution.

Further Details

Please contact Dr Kirsty Edgar (k.m.edgar@bham.ac.uk) for more project specific details. See the CENTA webpage for information on how to apply and general information. Check out the Palaeobiology and Palaeoclimate group webpages for more information on the group that you would be joining: https://www.birmingham.ac.uk/research/activity/earth-sciences/index.aspx or follow us on twitter @Palaeo_bham.