Sudden and Gradual Molluscan Extinctions in the Latest Cretaceous of Western European Tethys
Incompleteness of the fossil record has confounded attempts to establish the role of the end-Cretaceous bolide impact in the Late Cretaceous mass extinctions. Statistical analysis of latest Cretaceous outer-shelf macrofossils from western European Tethys reveals (i) a major extinction at or near the Cretaceous-Tertiary (K-T) boundary, probably caused by the impact, (ii) either a faunal abundance change or an extinction of up to nine ammonite species associated with a regression event shortly before the boundary, (iii) gradual extinction of most inoceramid bivalves well before the K-T boundary, and (iv) background extinction of approximately six ammonites throughout the latest Cretaceous.
Marshall
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C. R. Marshall, Department of Earth and Space Sciences, Molecular Biology Institute, and Institute for Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, USA. P. D. Ward, Department of Geological Sciences, AJ-20, University of Washington, Seattle, WA 98195, USA.
Ward
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