Raup D M, Jablonski D
Department of the Geophysical Sciences, University of Chicago, IL 60637.
Science. 1993 May 14;260:971-3. doi: 10.1126/science.11537491.
Analysis of the end-Cretaceous mass extinction, based on 3514 occurrences of 340 genera of marine bivalves (Mollusca), suggests that extinction intensities were uniformly global; no latitudinal gradients or other geographic patterns are detected. Elevated extinction intensities in some tropical areas are entirely a result of the distribution of one extinct group of highly specialized bivalves, the rudists. When rudists are omitted, intensities at those localities are statistically indistinguishable from those of both the rudist-free tropics and extratropical localities.
基于对340个海洋双壳类（软体动物门）属的3514个化石记录的分析，白垩纪末大灭绝事件表明，灭绝强度在全球范围内是一致的；未检测到纬度梯度或其他地理模式。一些热带地区较高的灭绝强度完全是由于一个已灭绝的高度特化双壳类群——厚壳蛤的分布所致。当排除厚壳蛤后，这些地区的灭绝强度在统计学上与无厚壳蛤的热带地区和温带地区的灭绝强度没有差异。
