The causes of mass extinctions and the nature of taxonomic radiations are central questions in paleobiology. Several episodes of taxonomic turnover in the fossil record, particularly the major mass extinctions, are generally thought to transcend known biases in the geologic record and are widely interpreted as distinct macroevolutionary phenomena that require unique forcing mechanisms. Here, by using a previously undescribed compilation of the durations of sedimentary rock sequences, I compare the rates of expansion and truncation of preserved marine sedimentary basins to rates of origination and extinction among Phanerozoic marine animal genera. Many features of the highly variable record of taxonomic first and last occurrences in the marine animal fossil record, including the major mass extinctions, the frequency distribution of genus longevities, and short-and long-term patterns of genus diversity, can be predicted on the basis of the temporal continuity and quantity of preserved sedimentary rock. Although these results suggest that geologically mediated sampling biases have distorted macroevolutionary patterns in the fossil record, preservation biases alone cannot easily explain the extent to which the sedimentary record duplicates paleobiological patterns. Instead, these results suggest that the processes responsible for producing variability in the sedimentary rock record, such as plate tectonics and sea-level change, may have been dominant and consistent macroevolutionary forces throughout the Phanerozoic.biodiversity ͉ mass extinction ͉ paleobiology ͉ sedimentary rock ͉ sequence stratigraphy O ne of the most striking aspects of the marine animal fossil record is that it preserves a volatile history of biodiversity and rates of taxonomic origination and extinction. Understanding the causes and evolutionary consequences of this volatility is one of the central goals of paleobiology. It has long been recognized, however, that the quantity of preserved sedimentary rock varies over short and long intervals of geologic time (1-3) and that this variation is correlated with several important macroevolutionary patterns in the fossil record, including changes in biodiversity (4-8) and rates of taxonomic extinction (4, 9, 10). The mutual correlations between preserved rock quantity and macroevolutionary patterns have been interpreted as evidence for either preservation biases that distort the apparent timings of extinction and origination in the fossil record (bias hypothesis) (4-7, 10) or a common pattern that is induced by processes, such as sea level fluctuations, plate tectonics, and resultant changes in marine shelf area, that affect both the amount of preserved rock and biological evolution (commoncause hypothesis) (6, 7, 9-12). Nevertheless, some workers have proffered that many intervals of turnover in the fossil record, particularly the major mass extinctions (13), are too substantial to be the result of preservation biases and are sufficiently distinct to require unique forcing mechanisms (14-17).Evaluati...