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1. Is Rarity Tied to Extinction During Background Intervals? A Case Study Using Mollusk Species From the Mid-Atlantic Coastal Plain Rowan Lockwood, Dept. of Geology, The College of William & Mary, P.O. Box 8795, Williamsburg, VA 23187 Ecological studies suggest that rare taxa are more likely to go extinct than abundant ones, but the relationship between rarity and extinction in the fossil record has received little attention. Mean Variability Occupancy • Are rare taxa more likely to go extinct? • Does the relationship between rarity and extinction differ in mass versus background extinctions? • Does selectivity differ according to metric of rarity? • Focusing on the record of Miocene and Pliocene mollusks from the mid-Atlantic Coastal Plain ** * ** ** * * Of the metrics assessed, geographic range yielded by far the strongest correlation with survivorship, while habitat breadth yielded the weakest. Species with large geographic ranges, high abundance, low variability in abundance, and high occupancy tend to have longer durations and are more likely to survive major extinction events such as the end-Cretaceous extinction (above) . tapestry.usgs.gov