Biogeographical and ecological patterns in bryozoans across the Cretaceous-Paleogene boundary: Implications for the phytoplankton collapse hypothesis

Abstract

Research Article| June 01, 2013 Biogeographical and ecological patterns in bryozoans across the Cretaceous-Paleogene boundary: Implications for the phytoplankton collapse hypothesis Caroline E. Sogot; Caroline E. Sogot 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK2Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK Search for other works by this author on: GSW Google Scholar Elizabeth M. Harper; Elizabeth M. Harper 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK Search for other works by this author on: GSW Google Scholar Paul D. Taylor Paul D. Taylor 2Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Caroline E. Sogot 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK2Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK Elizabeth M. Harper 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK Paul D. Taylor 2Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK Publisher: Geological Society of America Received: 06 Sep 2012 Revision Received: 21 Dec 2012 Accepted: 04 Jan 2013 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2013 Geological Society of America Geology (2013) 41 (6): 631–634. https://doi.org/10.1130/G34020.1 Article history Received: 06 Sep 2012 Revision Received: 21 Dec 2012 Accepted: 04 Jan 2013 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Caroline E. Sogot, Elizabeth M. Harper, Paul D. Taylor; Biogeographical and ecological patterns in bryozoans across the Cretaceous-Paleogene boundary: Implications for the phytoplankton collapse hypothesis. Geology 2013;; 41 (6): 631–634. doi: https://doi.org/10.1130/G34020.1 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 The hypothesized collapse in primary productivity associated with the Cretaceous-Paleogene (K-Pg) mass extinction would have been particularly severe on suspension feeders dependent on phytoplankton. Previous research on the ecological dynamics of erect bryozoans in the Danish Basin supported the phytoplankton crash hypothesis in showing a major postextinction increase in the skeletal biomass of cyclostome bryozoans relative to the more nutrient-demanding cheilostome bryozoans. New data on the ecological dynamics between these two bryozoan clades across the K-Pg boundary are provided to determine whether the postextinction cyclostome spike is also evident in encrusting bryozoans and over a greater geographical area. Changes across the K-Pg were quantified in encrusting bryozoans using three metrics: (1) abundance of colonies; (2) area of substrate covered; and (3) colony form. Data from the southeastern United States were added to those from Denmark to control for regional factors. Our analyses indicate a globally uniform change among encrusting bryozoans but without the strong postextinction cyclostome spike seen previously in Danish erect bryozoans. An increased proportion of sheet over runner cyclostome colonies was found in the lower Danian of Denmark and the southeastern United States, despite the expectation that runners with widely dispersed zooids should fare better in low nutrient conditions. Furthermore, weighed samples of erect bryozoans from the basal Danian of Maastricht (Netherlands) and the southeastern United States failed to reveal a strong cyclostome spike. These findings question the phytoplankton crash hypothesis, or at least the extent to which this kill mechanism influenced suspension feeders during the K-Pg mass extinction. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.