Organic-walled microfossil assemblages from glacial and interglacial Neoproterozoic units of Australia and Svalbard

Abstract

Research Article| November 01, 2014 Organic-walled microfossil assemblages from glacial and interglacial Neoproterozoic units of Australia and Svalbard Leigh Anne Riedman; Leigh Anne Riedman 1Department of Earth Science, University of California–Santa Barbara, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Susannah M. Porter; Susannah M. Porter 1Department of Earth Science, University of California–Santa Barbara, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Galen P. Halverson; Galen P. Halverson 2Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec H3A 2A7, Canada Search for other works by this author on: GSW Google Scholar Matthew T. Hurtgen; Matthew T. Hurtgen 3Department of Earth and Planetary Sciences, Northwestern University, Evanston, Illinois 60208, USA Search for other works by this author on: GSW Google Scholar Christopher K. Junium Christopher K. Junium 4Department of Earth Sciences, Syracuse University, Syracuse, New York 13244, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Leigh Anne Riedman 1Department of Earth Science, University of California–Santa Barbara, Santa Barbara, California 93106, USA Susannah M. Porter 1Department of Earth Science, University of California–Santa Barbara, Santa Barbara, California 93106, USA Galen P. Halverson 2Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec H3A 2A7, Canada Matthew T. Hurtgen 3Department of Earth and Planetary Sciences, Northwestern University, Evanston, Illinois 60208, USA Christopher K. Junium 4Department of Earth Sciences, Syracuse University, Syracuse, New York 13244, USA Publisher: Geological Society of America Received: 21 May 2014 Revision Received: 19 Aug 2014 Accepted: 21 Aug 2014 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2014 Geological Society of America Geology (2014) 42 (11): 1011–1014. https://doi.org/10.1130/G35901.1 Article history Received: 21 May 2014 Revision Received: 19 Aug 2014 Accepted: 21 Aug 2014 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Leigh Anne Riedman, Susannah M. Porter, Galen P. Halverson, Matthew T. Hurtgen, Christopher K. Junium; Organic-walled microfossil assemblages from glacial and interglacial Neoproterozoic units of Australia and Svalbard. Geology 2014;; 42 (11): 1011–1014. doi: https://doi.org/10.1130/G35901.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Before the onset of the Neoproterozoic Snowball Earth glaciations, eukaryotes had begun diversifying, and in their aftermath, macroscopic life, including both animals and macroalgae, became abundant and widespread. Although glacially driven mass extinctions have been hypothesized, little is known about the biosphere during and between these glaciations. Here we present new data from organic-walled microfossil assemblages from five successions in Australia and Svalbard that collectively span the first (Sturtian) glaciation and interglacial interval and integrate them with data derived from a critical evaluation of the literature to produce a new estimate of eukaryotic diversity from 850 to 650 Ma. These new glacial and interglacial assemblages consist of only smooth-walled spheroids (leiosphaerids), aggregates of cells, and filaments, in contrast to the much more diverse organic-walled microfossil assemblages found in early Neoproterozoic rocks. This contrast is not attributed to biases in deposition or preservation, but is instead interpreted as reflecting an interval of lowered eukaryotic diversity that spanned the glaciations and that may have begun millions of years prior to their onset. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.