Ever wonder why the dinosaurs disappeared? HHMI BioInteractive investigates the cause of the mass extinction at the end of the Cretaceous period—and the clues come from paleontology, chemistry, physics, and biology. This three-act film tells the story of the extraordinary detective work that solved one of the greatest scientific mysteries of all time. Explore the fossil evidence of these prehistoric animals, and other organisms that went extinct, through this lively educational video. See more HHMI BioInteractive short films and classroom resources here: http://www.hhmi.org/biointeractive/explore-short-films Free teacher resources supporting this short film can be found at http://www.hhmi.org/biointeractive/day-mesozoic-died