Origin and Morphology of the Eocene Planktonic Foraminifer Hantkenina

Research Article| July 01, 2003 ORIGIN AND MORPHOLOGY OF THE EOCENE PLANKTONIC FORAMINIFER HANTKENINA Helen K. Coxall; Helen K. Coxall 1Southampton Oceanography Centre, School of Ocean and Earth Science, European Way, Southampton, SO14 3ZH, UK. Email: hkc@soc.soton.ac.uk Search for other works by this author on: GSW Google Scholar Brian T. Huber; Brian T. Huber 2Department of Paleobiology, National Museum of Natural History, MRC-121, Smithsonian Institution, Washington, D.C. 20560, USA. Search for other works by this author on: GSW Google Scholar Paul N. Pearson Paul N. Pearson 3University of Bristol, Department of Earth Sciences, Wills Memorial Building, Queen’s Road, Bristol, BS8 1RJ, UK. Search for other works by this author on: GSW Google Scholar Author and Article Information Helen K. Coxall 1Southampton Oceanography Centre, School of Ocean and Earth Science, European Way, Southampton, SO14 3ZH, UK. Email: hkc@soc.soton.ac.uk Brian T. Huber 2Department of Paleobiology, National Museum of Natural History, MRC-121, Smithsonian Institution, Washington, D.C. 20560, USA. Paul N. Pearson 3University of Bristol, Department of Earth Sciences, Wills Memorial Building, Queen’s Road, Bristol, BS8 1RJ, UK. Publisher: Cushman Foundation for Foraminiferal Research Received: 15 Oct 2001 Accepted: 16 Apr 2002 First Online: 03 Mar 2017 Online ISSN: 1943-264X Print ISSN: 0096-1191 © 2003 Journal of Foraminiferal Research Journal of Foraminiferal Research (2003) 33 (3): 237–261. https://doi.org/10.2113/33.3.237 Article history Received: 15 Oct 2001 Accepted: 16 Apr 2002 First Online: 03 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 Helen K. Coxall, Brian T. Huber, Paul N. Pearson; ORIGIN AND MORPHOLOGY OF THE EOCENE PLANKTONIC FORAMINIFER HANTKENINA. Journal of Foraminiferal Research 2003;; 33 (3): 237–261. doi: https://doi.org/10.2113/33.3.237 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 SocietyJournal of Foraminiferal Research Search Advanced Search Abstract Study of the origin and early evolution of the tubulospine-bearing planktonic foraminiferal genus Hantkenina reveals that it evolved gradually from the clavate species Clavigerinella eocanica in the earliest middle Eocene and is unrelated to the genus Pseudohastigerina.Clavigerinella eocanica and the lower middle Eocene species Hantkenina nuttalli share many morphologic features and show similar developmental patterns but differ significantly in these aspects from P. micra. Rare, transitional Clavigerinella-Hantkenina forms from the Helvetikum section of Austria bridge the gap between clavate and tubulospinose morphologies, providing direct, stratigraphically-ordered evidence of the evolutionary transition between Hantkenina and Clavigerinella. Clavigerinellid ancestry is traced to a previously undescribed low-trochospiral species, Parasubbotina eoclava sp. nov., at Ocean Drilling Program Site 865.We speculate that Hantkenina originated through competition for limited food resources in a deep, oxygen-deficient habitat below the thermocline. The tubulospines may represent a structural adaptation to this new trophic strategy, allowing the organism to harvest a greater volume of water at minimal metabolic cost. The abrupt occurrence of Hantkenina in pelagic sediment cores from the central Pacific and other regions of the world ocean may represent immigration into these areas following speciation within the hydrographically evolving Tethys Seaway. Alternatively, cladogenesis may have occurred over a wider area, but due to a contemporaneous global hiatus the fossil record of this bioevent is poorly preserved. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.