Lead supervisor: Alex Liu, Earth Sciences
Co-supervisor: Nick Butterfield, Earth Sciences
Brief summary:
Investigate the role played by environmental and geographic conditions in facilitating the greatest radiation event in animal evolution.
Importance of the area of research concerned:
Fossils of early Cambrian age provide crucial insight into the early evolution and diversification of the animal phyla. Assemblages of small shelly fossils (SSFs), small carbonaceous fossils (SCFs), Burgess Shale Type biotas and trace fossils document a substantial radiation of animal diversity and disparity. Although much progress has been made in determining how Cambrian organisms relate to modern taxonomic groups, there remains uncertainty regarding what drove the Cambrian evolutionary ‘explosion’, and few studies have explored the palaeolatitudinal patterns and processes relating to evolution across this interval (e.g. Steiner et al., 2007; Na et al., 2022). Constraining the influence of environmental and palaeogeographic factors on taxon distribution will assist efforts to determine the controls on the tempo and mode of the Cambrian Explosion.
Project summary :
This project will compile available knowledge on the palaeogeographic distribution and preservational mode of early Cambrian taxa in Stages 3 and 4, between ~521–509 million years ago, to identify patterns in taxon and behavioural distributions, and to constrain the influence of palaeogeography on metazoan evolution across this critical interval. Building on previous projects within our group that have recognised strong environmental and latitudinal controls on late Ediacaran fossil distributions (Boddy et al., 2022), this project will determine the extent to which those factors shaped the latter stages of the Cambrian Explosion. Analysis of new data in combination with data already in hand will, for the first time, permit consideration of palaeolatitudinal influence on animal evolution across the entire Ediacaran-Cambrian transition.
What will the student do?:
You will compile palaeogeographic, age, biomineral and facies data for all occurrences of previously described genera of early Cambrian macrofossils (and ichnofossils) dating from the interval ~520–509 Ma, and plot the resulting information onto palaeogeographic reconstructions using ArcGIS and GPlates. Your dataset of Cambrian taxa will include information on their preservational mode, composition, and ecology. You will divide this dataset into suitable time bins to test hypotheses relating to the role of palaeogeography in controlling the distribution of metazoan innovations such as biomineralization, predation, and burrowing. Statistical tests will assess the strength of observed relationships. The data will be compared with comparable late Ediacaran (580–540Ma) and earliest Cambrian (540–521 Ma) data to determine the extent to which palaeolatitude shaped biogeographic patterns across the Ediacaran–Cambrian boundary, and the strength of results that can be inferred from such approaches (e.g. the impact of bioprovinciality evident in existing Cambrian datasets; Na et al., 2022).
References - references should provide further reading about the project:
Boddy, C.E., Mitchell, E.G., Merdith, A., & Liu, A.G. (2022). Palaeolatitudinal distribution of the Ediacaran macrobiota. Journal of the Geological Society, 179(1).
Na, L., Kocsis, Á.T., Li, Q., & Kiessling, W. (2023). Coupling of geographic range and provincialism in Cambrian marine invertebrates. Paleobiology, 49, 284-295.
Steiner, M., Li, G., Qian, Y., Zhu, M. & Erdtmann, B.D. (2007). Neoproterozoic to early Cambrian small shelly fossil assemblages and a revised biostratigraphic correlation of the Yangtze Platform (China). Palaeo3, 254, 67-99.
Applying
You can find out about applying for this project on the Department of Earth Sciences page.