Research Article| October 01, 2007 EXCEPTIONALLY PRESERVED LATE ALBIAN (CRETACEOUS) ARCELLACEANS (THECAMOEBIANS) FROM THE DAKOTA FORMATION NEAR LINCOLN, NEBRASKA, USA P. J. van Hengstum; P. J. van Hengstum 4 1School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada. 4Correspondence author. E-mail: vanhenp@mcmaster.ca Search for other works by this author on: GSW Google Scholar E. G. Reinhardt; E. G. Reinhardt 1School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada. Search for other works by this author on: GSW Google Scholar F. S. Medioli; F. S. Medioli 2Centre for Marine Geology, Dalhousie University, Halifax, Nova Scotia, B3H 3J5, Canada. Search for other works by this author on: GSW Google Scholar D. R. Gröcke D. R. Gröcke 3Department of Earth Sciences, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, UK. Search for other works by this author on: GSW Google Scholar Author and Article Information P. J. van Hengstum 4 1School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada. E. G. Reinhardt 1School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada. F. S. Medioli 2Centre for Marine Geology, Dalhousie University, Halifax, Nova Scotia, B3H 3J5, Canada. D. R. Gröcke 3Department of Earth Sciences, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, UK. 4Correspondence author. E-mail: vanhenp@mcmaster.ca Publisher: Cushman Foundation for Foraminiferal Research Received: 08 Jan 2007 Accepted: 25 May 2007 First Online: 03 Mar 2017 Online ISSN: 1943-264X Print ISSN: 0096-1191 © 2007 Journal of Foraminiferal Research Journal of Foraminiferal Research (2007) 37 (4): 300–308. https://doi.org/10.2113/gsjfr.37.4.300 Article history Received: 08 Jan 2007 Accepted: 25 May 2007 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 P. J. van Hengstum, E. G. Reinhardt, F. S. Medioli, D. R. Gröcke; EXCEPTIONALLY PRESERVED LATE ALBIAN (CRETACEOUS) ARCELLACEANS (THECAMOEBIANS) FROM THE DAKOTA FORMATION NEAR LINCOLN, NEBRASKA, USA. Journal of Foraminiferal Research 2007;; 37 (4): 300–308. doi: https://doi.org/10.2113/gsjfr.37.4.300 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 Thousands of exceptionally well-preserved Arcellaceans (Thecamoebians) have been recovered from a Late Albian (Cretaceous) deposit. Sedimentary samples were obtained from a clayey-silt leaf bed in the Dakota Formation, outcropping in a clay pit excavated by the Yankee Hill Brick Company, located near Lincoln, Nebraska. Based on recovered freshwater macrophyte spore and fossil remains, the leaf bed is a lagerstätten of paleobotanical remains in which the paleoenvironment has been interpreted as a quiescent freshwater setting. The large number of recovered thecamoebians revealed a high intraspecific variability in test morphology that is comparable to Holocene thecamoebian populations. Consequently, we employ the thecamoebian strain taxonomic framework, a first for ancient thecamoebians. Extant species contained in this collection include Difflugia oblonga, Difflugia protaeiformis, Difflugia urens, Pontigulasia compressa, Lagenodifflugia vas, Cucurbitella tricuspis, Lesquereusia spiralis and the cysts of environmentally stressed protozoans—with only one new species reported, Difflugia baukalabastron. The well-preserved nature of the taxa, suggesting little taphonomic bias, and the lack of significant new species supports the current hypothesis of minimal evolution in thecamoebian lineages through geologic time. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.