Causes and consequences of a middle Pleistocene origin of the modern planktonic foraminifer Neogloboquadrina pachyderma sinistral

Research Article| June 01, 2002 Causes and consequences of a middle Pleistocene origin of the modern planktonic foraminifer Neogloboquadrina pachyderma sinistral Michal Kucera; Michal Kucera 1Department of Geology, Royal Holloway University of London, Egham TW20 0EX, UK Search for other works by this author on: GSW Google Scholar James P. Kennett James P. Kennett 2Department of Geological Sciences and Marine Science Institute, University of California, Santa Barbara, California 93106, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Michal Kucera 1Department of Geology, Royal Holloway University of London, Egham TW20 0EX, UK James P. Kennett 2Department of Geological Sciences and Marine Science Institute, University of California, Santa Barbara, California 93106, USA Publisher: Geological Society of America Received: 01 Nov 2001 Revision Received: 27 Feb 2002 Accepted: 03 Mar 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (6): 539–542. https://doi.org/10.1130/0091-7613(2002)030<0539:CACOAM>2.0.CO;2 Article history Received: 01 Nov 2001 Revision Received: 27 Feb 2002 Accepted: 03 Mar 2002 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Michal Kucera, James P. Kennett; Causes and consequences of a middle Pleistocene origin of the modern planktonic foraminifer Neogloboquadrina pachyderma sinistral. Geology 2002;; 30 (6): 539–542. doi: https://doi.org/10.1130/0091-7613(2002)030<0539:CACOAM>2.0.CO;2 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 Switches in coiling direction of shells of the planktonic foraminifer Neogloboquadrina pachyderma have been extensively used as a paleotemperature proxy from the late Miocene through the Quaternary, exploiting the specific modern polar affinity of the sinistrally coiled form. Here we have reexamined the origin of the modern sinistral form in Pliocene and Pleistocene sediments from Ocean Drilling Program Site 1014 in the eastern North Pacific. By using morphometric and stable isotope data, we show that Pliocene and Pleistocene sinistral forms of N. pachyderma are morphologically and ecologically different and that modern-type sinistral form first appeared ca. 1 Ma. These findings suggest that N. pachyderma sinistral should not be used for calibrated paleoceanographic reconstructions prior to the middle Pleistocene and reinforce the need to assess the origin of specific ecological affinities of other modern planktonic foraminifer species. The first appearance of the modern form and the subsequent evolution of its mean shell size appear to have been synchronous in the North Pacific and the North Atlantic. Such hemispheric evolutionary synchronicity implies existence of trans-Arctic gene flow. The modern-type shell morphology and the specific cold-water affinity of N. pachyderma sinistral may have evolved in response to the onset of the 100 k.y. climate regime in the middle Pleistocene. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.