There is no single, unifying description of a keystone species — these animals come in all sizes, across all continents, and impact their ecosystems in wildly different ways. To showcase this diversity, the Keystone Species Sampler interactive takes 15 keystones from across the globe and condenses their backgrounds into an easy-to-read tour of ecosystem research. From the southern reaches of Patagonia to the islands of the Indian Ocean, students are invited to explore a wide range of stories that showcase why “keystone” is a critical term in understanding how systems function.