Drivers of marine ecosystem change during the end-Triassic mass extinction and recovery

Mass extinctions were critical turning points in the history of life and those that occurred during episodes of sudden climate warming record a similar suite of co-occurring, interlinked environmental changes (Jaraula et al., 2013). A key challenge is to determine which of these factors were most important in driving extinction, recovery and ecological change (Danise et al., 2015). One of the most important such crises occurred at the end of the Triassic (~201.5 Ma), driven by catastrophic release of greenhouse gases (Kasprak et al., 2015). Although a number of studies have separately investigated global changes in the biosphere and geosphere during this event, a detailed understanding of how marine ecosystems responded to climate-related abiotic changes during the extinction, its aftermath and subsequent recovery is lacking.

The student will rectify this knowledge gap by using palaeoecological data to generate time series of quantitative marine ecosystem change, from a range of different sites. These data will be integrated with geochemical proxy data from the same samples. Key hypotheses to test include (a) whether temperature change or expanding anoxic dead zones are the most important drivers of marine ecosystem change and (b) whether benthic and pelagic organisms responded to similar or different drivers.

The student will collect and analyse palaeoecological samples from coastal and mountain outcrops and available sediment cores from the UK (southwest England, South Wales, and Northern Ireland) and Central Europe (Austria, Germany) using a multidisciplinary approach. Species abundance and body size data of fossil benthic and nektonic macroinvertebrates will be collected and used to quantify ecological changes in the structure and function of the marine fossil communities. These data will be compared to a suite of geochemical environmental proxy data for parameters such as sea surface temperature, water column stratification, salinity, redox potential, carbon and nutrient cycling, in order to determine which abiotic factors are most important drivers of biotic change. Samples will be selected from sedimentary sequences known to contain abundant and well preserved fossils, and which are also known to be of relatively low thermal maturity, so that palaeontological and geochemical data can be obtained from the same samples.

The SPITFIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at Natural History Museum (NHM) and School of Ocean and Earth Science. The successful candidate will be trained in basic and advanced techniques of palaeontological data collection and analysis. Student participation in expeditions to locations in the UK and Europe will provide field research experience. Significant time will be spent in the NHM, where the student will receive training in macroinvertebrate taxonomy, collections and data management, as well as outreach and public engagement.