RECONSTRUCTING GEOGRAPHIC RANGE SIZE DYNAMICS FROM FOSSIL DATA

Ecologists and paleontologists alike are increasingly using the fossil record as a spatial dataset, in particular to study the dynamics and distribution of geographic range sizes among fossil taxa. However, no attempts have yet been made to establish how accurately range sizes and range-size dynamics can be preserved in fossil locality data, and which methods reconstruct these most accurately and reliably. We develop a new simulation-based methodological framework for testing the accuracy of commonly-used paleo-range size reconstruction methods (max. latitudinal range, max. great circle distance, convex hull, and alpha convex hull) in different extinction-related biogeographic scenarios. We find that max. great circle distance and convex hull methods most reliably capture changes in range size at low numbers of simulated fossil sites, whereas max. great circle distance and max. latitudinal range perform best at predicting the distribution of ‘victims’ and ‘survivors’ in hypothetical extinction scenarios. Our results suggest that macroevolutionary and macroecological patterns can be studied reliably using only a few fossil occurrence sites, providing validation for a large swathe of paleo-range studies in the literature. More broadly, with a suite of modifications, our approach provides the opportunity to systematically calibrate the quality of the spatial fossil record in specific environments and time intervals, and delineate the conditions under which paleobiologists can use fossil locality data to reconstruct paleobiogeographical, macroecological, and macroevolutionary patterns over critical intervals in Earth History.