Marshall CR, Ward PD
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.
Science. 1996 Nov 22;274(5291):1360-3. doi: 10.1126/science.274.5291.1360.
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.
化石记录的不完整性使得人们难以确定白垩纪末期的火流星撞击在晚白垩世大灭绝事件中所起的作用。对来自西欧特提斯地区的最新白垩纪外陆架大型化石进行的统计分析显示：（i）在白垩纪-古近纪（K-T）边界处或附近发生了一次重大灭绝事件，可能是由撞击导致的；（ii）在边界之前不久，伴随着一次海退事件，多达9种菊石物种出现了动物群数量变化或灭绝；（iii）在K-T边界之前很久，大多数厚壳蛤双壳类动物就逐渐灭绝了；（iv）在整个最新白垩纪期间，大约有6种菊石出现了背景灭绝现象。
