THE USE OF GEOGRAPHIC INFORMATION SYSTEMS IN STUDIES ON THE COMPLETENESS OF THE FOSSIL RECORD

Many recent studies have identified positive correlations between fossil occurrences and the amount of sedimentary rock preserved per geological time bin. There are two competing explanations for this persistent covariation: (1) the fossil record is severely biased by the amount of sedimentary rock preserved per time period; (2) both the rock and fossil records have been driven simultaneously by an environmental common-cause mechanism. However, most studies have used vague and imprecise geological data at global and continental scales, often in the form of counts of fossiliferous formations downloaded from the Paleobiology Database (PBDB). Formation counts have been criticised for a number of reasons, including (1) they vary in extent and thickness over many orders of magnitude; (2) they do not correlate with rock accessibility or collection effort; (3) they often depend on fossil abundance, so are not independent of diversity. It is also evident that formation counts downloaded directly from the PBDB suffer from missing data, synonymous entries, and spelling mistakes. Geographic Information Systems (GIS) offer a powerful spatial analysis tool to assess the completeness of the fossil record through geological time, but have thus far been sparingly used. In combination with digital geological data (i.e. British Geological Survey digital maps) and paleontological data (i.e. Paleobiology Database), GIS can be used to directly compare the rock and fossil records as well as adding a critical spatial dimension where previous studies have simply analysed diversity metrics through time. This approach promises to contribute massively to our understanding of macroevolutionary events through deep time.