Projected climate change poses a large threat to ecosystems and species, but it is hard to know how to prioritize conservation efforts. This is where paleontology can be helpful in informing policy, ecology, and conservation. By exploring how animals have reacted to historic environmental changes, we can begin to predict which species will be most affected today. In doing so, we can prioritize where and how we should spend our resources to maximally protect biodiversity. If an animal is forced to shift where it lives in response to changing climates, it is difficult to tell whether a reduction in its geographic range is a typical reaction to that stressor or whether the species' range contraction may be leading to ultimate extinction. My research will examine past range contractions to establish a signal that indicates when a species is likely to go extinct. The signal will then be applied to modern range contractions to predict species' vulnerability to extinction.