Data were collected by Jonathan Payne, Demir Altiner, and Mindi Summers. Questions should be directed to Jonathan Payne (jlpayne@stanford.edu). payne_occurrence_size.txt - tab delimited text file containing list of occurrences and specimen sizes for each sample payne_abundance.txt - tab delimited text file containing list of specimen counts by genus for each sample payne_occurrence_size.txt data fields: Sample - sample number of rock from which thin section was prepared Photograph - unique identified of photograph containing measured specimen Size (um) - maximum dimension of photographed specimen, in microns Gen. res. - taxonomic resolution of genus assignment Genus - Name of genus to which specimen was assigned Spec. res. - taxonomic resolution of species assignment Species - name of species to which specimen was assigned Substage - geological substage to which sample belongs Age - age of the sample in millions of years payne_abundance.txt data fields: Environment - whether sample represents a platform interior or basin margin depositional environment Sample - sample number of rock from which thin section was prepared Substage - geological substage to which sample belongs Genus - name of the genus Specimens - number of individuals assignable to that genus in that sample