2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 42-1
Presentation Time: 9:00 AM-5:30 PM


WALKER, Fiona1, DUNHILL, Alexander M.2, WOODS, Mark A.3, NEWELL, Andrew J.4 and BENTON, Michael J.1, (1)School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom, (2)School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom, (3)British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham, NG12 5GG, United Kingdom, (4)British Geological Survey, Maclean Building, Crowmarsh Gifford, Wallingford, OX10 8BB, United Kingdom, a.dunhill@leeds.ac.uk

The fossil record captures past biodiversity imperfectly. Does sampling bias obscure biological diversity signals in palaeontological richness data? Global studies find a correlation between sampling proxies and sampled fossil diversity. However, regional studies find that this relationship breaks down on small scales, or that the strength of this relationship depends on the taxon, tectonic and depositional setting and rock exposure. The relationship between global (gamma) and local (alpha) diversity measures is of course modified by inter-regional differentiation (beta diversity), but comparisons across scales are intriguing. A newly-compiled dataset of fossil occurrences from the Chalk of Hampshire, UK, is presented. Analysis of diversity in this succession per formation and per map square reveals a correlation between diversity and sampling effort measured at this scale. Genus richness counts are driven by sampling bias in this dataset, but this masks real local faunal turnover as demonstrated by the episodic nature of species distributions in the Chalk and similarity indices for each formation.