Geological Society of America

T184 Geobiology of Earth-Life Systems I

Tuesday, 27 September 2016
8:00 AM - 12:00 PM
Room 503

EXCEPTIONALLY PRESERVED FOSSIL ASSEMBLAGES THROUGH GEOLOGIC TIME AND SPACE

Paper number: T184-13
Program: Technical Sessions
Time: 11:00 AM – 11:15 AM

Authors

A. Drew Muscente Presenting Author
Harvard University, Cambridge, MA
Shuhai Xiao
Virginia Polytechnic Institute and State University, Blacksburg, VA
Marc Laflamme
University of Toronto Mississauga, Mississauga, ON
James Schiffbauer
University of Missouri, Columbia, MO
Jesse S. Broce
University of Missouri, Columbia, MO
Kenneth H. O'Donnell
Germantown, MD
Thomas Boag
Stanford University Department of Geological Sciences, Stanford, CA
Michael Meyer
Carnegie Institution of Washington, Washington, DC, DC
Andrew D. Hawkins
Virginia Tech, Blacksburg, VA
John Huntley
University of Missouri, Columbia, MO

Abstract

Exceptionally preserved fossils of non-biomineralized tissues provide key insights into anatomies and communities of ancient organisms. Assemblages of such fossils are not evenly distributed through geologic time or space, suggesting exceptional fossil preservation is controlled by factors operating on global scales. Establishing the influence of global factors, however, requires documentation of temporal and spatial trends in the occurrences of such assemblages through the geologic history of complex life. To this end, we compiled and analyzed a dataset of 694 globally distributed fossil assemblages from ~610 to 3 Ma (Mega anna). Our analyses show that clusters of exceptional fossil assemblages decline in number and shift from open marine to restricted (transitional and non-marine) depositional settings through the Ediacaran-Silurian (635–420 Ma) interval in concert with increasing oxygenation of the ocean-atmosphere system and development of bioturbation. Thereafter, clusters of exceptional fossil assemblages generally rise in number through the Devonian-Neogene (420–3 Ma) interval with increasing non-marine sedimentary rock quantity and improving geologic sampling. Secular environmental transitions and rock record biases, thus, overprint the distribution of exceptionally preserved fossil assemblages in geologic time and space. Overall, our study affirms the importance of low oxygen and bioturbation levels in the conservation of non-biomineralized tissues, demonstrates the role of rock record bias in the exceptional fossil record, and provides fundamental bases for understanding occurrences of exceptionally preserved fossils through time and space.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-282405

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