Illuminating the origins of complex life: Spatial analysis of Ediacaran ecosystems

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• Dr Emily Mitchell (Department of Earth Sciences, University of Cambridge)
• Monday 12 February 2018, 17:30-18:30
• Harker 1, Department of Earth Sciences, Downing Street.

If you have a question about this talk, please contact Charlie Eardley.

Ediacaran macro-organisms occupy a crucial position in the history of life on Earth, marking the transition between the microbially dominated Proterozoic and the Cambrian explosion of modern animals. The oldest Ediacaran macro-organisms exhibit unique morphologies, making it difficult to resolve their phylogenetic relationships or their basic ecology. However, the sessile nature of these Ediacaran macro-organisms, coupled with their in-situ preservation, means that their spatial positions reflect the biological and ecological processes that they were subject to in-life. As a result, detailed spatial analyses moves beyond descriptive statistics, enabling verifiable predictions to be made and ecological hypotheses to be tested.

Using a high-resolution tripod-mounted Laser Line Probe, we have comprehensively mapped 18 of the most diverse and abundant Ediacaran communities across Newfoundland, Canada and Charnwood Forest, UK, to a resolution of ~40 µm. By analysing the relationship of specimen height with spatial distributions, we found that competition for water-column resources did not structure these ecosystems, with the key advantage of large body-size limited to greater dispersal, contrary to previous suggestions. Furthermore, stemmed organisms do not exhibit any tiering, in contrast to non-stemmed organisms, illustrating that this morphological differentiation was also not driven by resource competition but by reproductive concerns.

This talk is part of the Sedgwick Club talks series.

This talk is included in these lists:

• Harker 1, Department of Earth Sciences, Downing Street
• Department of Earth Sciences seminars
• Sedgwick Club talks

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