Data from: 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 been made to establish how accurately range sizes and range-size dynamics can be preserved. Two fundamental questions are: can common paleo-range reconstruction methods accurately reproduce known species’ ranges from locality (i.e., point) data, and, are some reconstruction methods more reliable than others? Here, we develop a methodological framework for testing the accuracy of commonly-used paleo-range size reconstruction methods (maximum latitudinal range, maximum great circle distance, convex hull, and alpha convex hull) in different extinction-related biogeographic scenarios. We use the current distribution of surface water bodies as a proxy for ‘preservable area’, thus constructing a best-case scenario in which to test the performance of the four methods. We find that maximum great circle distance and convex hull methods most reliably capture changes in range size at low numbers of fossil sites, whereas convex hull performs best at predicting the distribution of ‘victims’ and ‘survivors’ in hypothetical extinction scenarios. Our results suggest that macroevolutionary and macroecological patterns in the relatively recent past can be studied reliably using only a few fossil occurrence sites. The accuracy of range-size reconstruction undoubtedly changes though time with the distribution and area of fossiliferous sediments, and our approach thus provides the opportunity to systematically calibrate the quality of the spatial fossil record in specific environments and time intervals, and to delineate the conditions under which paleobiologists can reconstruct paleobiogeographical, macroecological, and macroevolutionary patterns over critical intervals in Earth History.生态学家与古生物学家愈发多地将化石记录作为空间数据集加以应用，尤其致力于探究化石类群的地理分布范围面积的动态变化与分布格局。然而，目前尚无研究明确分布范围面积及其动态变化的保存精度究竟如何。学界存在两个核心问题：其一，主流古地理分布范围重建方法能否通过位点（即点位）数据精准还原已知物种的分布范围？其二，不同重建方法的可靠性是否存在差异？本研究构建了一套方法学框架，用于检验四种常用古分布范围面积重建方法——最大纬度范围法、最大大圆距离法、凸包法（convex hull）与α凸包法（alpha convex hull）——在不同灭绝相关生物地理情景下的重建精度。本研究以当前地表水体的分布作为‘可保存区域’的替代指标，以此构建最优测试情景，用于评估四种方法的表现。研究结果显示，在化石位点数量较少的情况下，最大大圆距离法与凸包法能够最可靠地反映分布范围面积的变化；而在假设的灭绝情景中，凸包法在预测‘灭绝类群’与‘幸存类群’的分布格局方面表现最优。本研究结果表明，仅依靠少量化石产出位点，即可可靠地探究距今较近时期的宏观进化与宏观生态格局。毋庸置疑，分布范围面积的重建精度无疑会随时间推移，随着含化石沉积物的分布与面积变化而改变，因此本研究的方法框架为我们提供了系统校准特定环境与时间区间内空间化石记录质量的途径，同时也能够明确古生物学家在地球历史关键时段内重建古生物地理、宏观生态与宏观进化格局所需的适宜条件。