Professor Sarah Gabbott and Professor Mark Williams
The Early Cambrian Chengjiang biota in Yunnan Province, China preserves the fossilized remains of a diverse and ecologically complex early Cambrian marine ecosystem. Not only are fossils exceptionally preserved, revealing intimate ecological animal interactions such as predation and symbiosis but their age occurring in the immediate aftermath of the Cambrian evolutionary ‘explosion’ makes them our most valuable resource in exploring early animal evolution in deeptime.
However, all the ecological and evolutionary narrative that we can extract from the biota must be viewed with an understanding of the preservation processes (taphonomy) that led to carcasses becoming fossils. Without this we risk seriously biasing and distorting our view of Cambrian life in this interval. Initial work showed that decay inhibition and the growth of iron pyrite on decaying carcasses was important in preserving the fossils, but now the opportunity is ripe to take these studies much further. In this project the student will use new state-of-the art micro-CT techniques, combined with Scanning Electron Microscopy to investigate the preservational processes in more detail and across a wider range of fossil groups than has been done previously. Selected fossils will provide information on how a variety of anatomical features are preserved and comparisons across fossils and different depositional basins will reveal how fossils became preserved allowing the student to determine: how much anatomy is lost to decay and where it is preserved which tissue types are preserved and how?;
Our ultimate goal, and one which in the Chengjiang is achievable, is to be able to explore how fossilization affects the evolutionary position of taxa on the tree of life (especially arthropods), and to what extent the Chengjiang biota represents the complete living community, or a biased version of this with taxa being absent owing to non-preservation.
The student will benefit from joining a dynamic group of palaeontologists who investigate the Chengjiang biota. Sarah Gabbott and Mark Williams will provide supervision of the taphonomy and arthropod anatomy, respectively. In Yunnan University Dayou Zhai and Lio Liu (from Yunnan Key Laboratory for Palaeontology, YKLP) will teach the student micro-CT and fluorescence imaging. In addition, a new Chinese PhD studentship (funded by Yunnan University) will investigate a different but related project. We plan exchange visits and close collaboration between both students to support their scientific training and development and to foster strong, mutually-beneficial collaboration between research groups.
1. Hou, X.-G., Siveter, D. J., Siveter, D. J., Aldridge, R. J., Cong, P.-Y., Gabbott, S. E., Ma, X., Purnell, M. A.; Williams, M. 2017: The Cambrian fossils of Chengjiang, China. The flowering of early animal life (2nd edition). 328 pp. Wiley-Blackwell.
2. Gaines, R.R., Emma U. Hammarlund, E.U., Xianguang Hou, Changshi Qie, Gabbott, S.E., Yuanlong Zhaog, Jin Pengg, and Canfield, D.E. (2012). Mechanism for Burgess Shale-type preservation. Proceedings of the National Academy of Sciences, USA, 109, E1902.
3. Gabbott., S. E., Norry., J, M., Hou., Xian-guang., Siveter, D. J. (2004). Preservation of Lower Cambrian animals of the Chengjiang biota. Geology, 32(10), 901-904.