1997/05/01 by Jeffrey G. Eaton, James I. Kirkland, J. Howard Hutchison +4 · 5 citations
Earth and Planetary Sciences · #Paleontology and Stratigraphy of Fossils #Geological formations and processes #Geology and Paleoclimatology Research
paper · doi:10.1130/0016-7606(1997)109<0560:neatct>2.3.co;2
Research Article| May 01, 1997 Nonmarine extinction across the Cenomanian-Turonian boundary, southwestern Utah, with a comparison to the Cretaceous-Tertiary extinction event Jeffrey G. Eaton; Jeffrey G. Eaton 1Department of Geosciences, Weber State University, Ogden, Utah 84408-2507 Search for other works by this author on: GSW Google Scholar James I. Kirkland; James I. Kirkland 2Dinamation International Society, 550 Crossroads Court, Fruita, Colorado 81521 Search for other works by this author on: GSW Google Scholar J. Howard Hutchison; J. Howard Hutchison 3Museum of Paleontology, University of California, Berkeley, California 94720 Search for other works by this author on: GSW Google Scholar Robert Denton; Robert Denton 4New Jersey State Museum, Trenton, New Jersey 08625-0530 Search for other works by this author on: GSW Google Scholar Robert C. O'Neill; Robert C. O'Neill 4New Jersey State Museum, Trenton, New Jersey 08625-0530 Search for other works by this author on: GSW Google Scholar J. Michael Parrish J. Michael Parrish 5Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois 60115 Search for other works by this author on: GSW Google Scholar Author and Article Information Jeffrey G. Eaton 1Department of Geosciences, Weber State University, Ogden, Utah 84408-2507 James I. Kirkland 2Dinamation International Society, 550 Crossroads Court, Fruita, Colorado 81521 J. Howard Hutchison 3Museum of Paleontology, University of California, Berkeley, California 94720 Robert Denton 4New Jersey State Museum, Trenton, New Jersey 08625-0530 Robert C. O'Neill 4New Jersey State Museum, Trenton, New Jersey 08625-0530 J. Michael Parrish 5Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois 60115 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1997) 109 (5): 560–567. https://doi.org/10.1130/0016-7606(1997)109<0560:NEATCT>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jeffrey G. Eaton, James I. Kirkland, J. Howard Hutchison, Robert Denton, Robert C. O'Neill, J. Michael Parrish; Nonmarine extinction across the Cenomanian-Turonian boundary, southwestern Utah, with a comparison to the Cretaceous-Tertiary extinction event. GSA Bulletin 1997;; 109 (5): 560–567. doi: https://doi.org/10.1130/0016-7606(1997)109<0560:NEATCT>2.3.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 SocietyGSA Bulletin Search Advanced Search Abstract There is a marked, possibly stepwise, extinction of marine taxa across the Cenomanian-Turonian boundary. Across the boundary in southwestern Utah, there is only minor species-level extinction of brackish-water taxa, and an actual increase in diversity of fully terrestrial organisms; significant family-level extinctions are restricted to aquatic taxa such as fishes and turtles.It is not possible in the nonmarine setting to determine if this is a gradual, stepwise, or instantaneous extinction, or to what degree it correlates to marine extinction events. Nonmarine faunas underwent no major change during the transgressive phase of the Greenhorn cycle, and the loss of aquatic taxa along with displacement (but not extinction) of brackish-water vertebrates and some marsupial mammals is first apparent in rocks deposited during regression in the Turonian. The loss of flood-plain habitat at maximum transgression may have caused the extinction of some of the aquatic taxa. The absence but not extinction of certain taxa on flood plains during the Greenhorn regression suggests that there may be some significant difference in transgressive and regressive flood plains. Drawdown increases the gradients of rivers and results in incision along coastal margins. This restricts the extent of brackish-water environments and may have had an impact on faunal compositions of riverine systems and contributed to extinction within aquatic communities.This pattern is quite different from that at the Cretaceous-Tertiary (K-T) boundary. Aquatic taxa underwent relatively minor losses at that boundary, whereas terrestrial organisms underwent major extinction. It appears that much of the Late Cretaceous aquatic community was restructured (mostly by exclusion of many taxa rather than extinction) and reduced in diversity during large-scale regression in the middle of the Maastrichtian before the end of the Cretaceous. This aquatic community was living in a rapidly expanding environment (overall regression of marine waters) at the K-T boundary. The extinction of terrestrial taxa at the boundary is unlike the pattern observed at the Cenomanian-Turonian boundary and suggests that some mechanism other than eustatic change played a significant role in the extinction. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.