Sampling, species abundance, and the stratigraphic signature, of mass extinction: A test using Holocene tidal flat molluscs

Research Article| September 01, 1990 Sampling, species abundance, and the stratigraphic signature, of mass extinction: A test using Holocene tidal flat molluscs Keith H. Meldahl Keith H. Meldahl 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Geology (1990) 18 (9): 890–893. https://doi.org/10.1130/0091-7613(1990)0182.3.CO;2 Article history first online: 02 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 Keith H. Meldahl; Sampling, species abundance, and the stratigraphic signature, of mass extinction: A test using Holocene tidal flat molluscs. Geology 1990;; 18 (9): 890–893. doi: https://doi.org/10.1130/0091-7613(1990)0182.3.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 SocietyGeology Search Advanced Search Abstract Assume that a catastrophe caused the sudden extinction of the molluscan biota of a Holocene tidal flat. Would this event be recorded accurately in the stratigraphic record? How accurately would the extinction of rare species be recorded? How would sudden, gradual, and stepwise patterns of extinction compare? Bivalve and gastropod species occurrences were recorded from eight tidal channel sediment cores (up to 70 cm long) from Bahia la Choya, northern Gulf of California. The distribution of last occurrences of 45 species suggests that a sudden extinction would appear to be gradual in the stratigraphic record, due to error in biostratigraphic range end-points (Signor-Lipps effect). Extinction is typically not accurately recorded for species with less than 15% stratigraphic abundance (i.e., occurring in less than 15% of the sample intervals; 71% of the species). The data were subjected to simulations of stepwise and gradual extinction. Differences between the sudden, stepwise, and gradual scenarios are apparent in (1) frequency distributions of biostratigraphic last occurrences, (2) graphic relations between stratigraphic abundance and last occurrence, and (3) patterns of apparent diversity decline below the extinction boundary. Extinction studies in outcrops and cores could utilize last occurrence and stratigraphic abundance data (readily available in the fossil record) to distinguish among sudden, stepwise, and gradual patterns of 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.