Stable isotopic evidence of salinity change: Influence on the evolution of melanopsid gastropods in the late Miocene Pannonian basin

Research Article| November 01, 1989 Stable isotopic evidence of salinity change: Influence on the evolution of melanopsid gastropods in the late Miocene Pannonian basin Dana H. Geary; Dana H. Geary 1Department of Geology and Geophysics, 1215 W. Dayton Street, University of Wisconsin, Madison, Wisconsin 53706 Search for other works by this author on: GSW Google Scholar Julieanne Rich; Julieanne Rich 1Department of Geology and Geophysics, 1215 W. Dayton Street, University of Wisconsin, Madison, Wisconsin 53706 Search for other works by this author on: GSW Google Scholar John W. Valley; John W. Valley 1Department of Geology and Geophysics, 1215 W. Dayton Street, University of Wisconsin, Madison, Wisconsin 53706 Search for other works by this author on: GSW Google Scholar Kevin Baker Kevin Baker 1Department of Geology and Geophysics, 1215 W. Dayton Street, University of Wisconsin, Madison, Wisconsin 53706 Search for other works by this author on: GSW Google Scholar Geology (1989) 17 (11): 981–985. https://doi.org/10.1130/0091-7613(1989)017<0981:SIEOSC>2.3.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 Dana H. Geary, Julieanne Rich, John W. Valley, Kevin Baker; Stable isotopic evidence of salinity change: Influence on the evolution of melanopsid gastropods in the late Miocene Pannonian basin. Geology 1989;; 17 (11): 981–985. doi: https://doi.org/10.1130/0091-7613(1989)017<0981:SIEOSC>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 SocietyGeology Search Advanced Search Abstract The radiation of the gastropod Melanopsis in the Pannonian basin of eastern and central Europe provides an excellent case study of the tempo and mechanisms of evolutionary diversification. We analyzed the carbon and oxygen isotopic ratios of melanopsid shells from before, during, and after the radiation in order to provide a more detailed paleoenvironmental framework in which to interpret the morphological changes observed. Our samples fall into two groups: those from before and during the radiation (late Sarmatian and Pannonian stages) form a tight cluster; a second, more scattered group of points represents samples from after the radiation (Pontian Stage). The late Sarmatian-Pannonian samples have higher ratios of both isotopes (means of -2.11 for δ18O, and 1.27 for δ13C) than do the succeeding Pontian Stage samples (-4.16 and -2.22, respectively). We interpret this shift as indicative of a basinwide drop in salinity, an interpretation supported by paleofaunal evidence. Our isotopic data refine the environmental scenario in two important ways. The tight cluster of late Sarmatian-Pannonian data indicates that the shallow waters of the basin were relatively uniform and relatively stable with respect to salinity, rather than locally variable or steadily changing across this time interval. The shift to fresher water in the Pontian Stage coincides with the extinction of two widespread and abundant melanopsid species, but several species go extinct earlier than the salinity drop, and two species pass through it seemingly unaffected. 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.