Rocks, Fossils, and Ecology: Understanding How Time Is Sampled in the Fossil Record

The geological record provides us with absolute ages of past events and organisms, but it also contains information about what occurred within time intervals ranging from seconds to eons. Within this huge range of time samples, intervals that span days to tens of thousands of years can be the hardest to calibrate in convincing ways, yet knowing how much time is recorded in fossil samples is essential for reconstructing terrestrial and marine paleoecology. A career of field research in sedimentology, stratigraphy, paleontology, observations and experiments in modern land ecosystems (neo-taphonomy), and comparisons of fossil preservation across the Phanerozoic record has convinced me that we can make credible estimates of time intervals represented by different types of fossil assemblages. The examples in this autobiographical review trace the development of my understanding of time-averaging in the fossil record and suggest how future research can unlock new information about ancient ecosystems and their inhabitants.