This activity explores the concepts and research presented in the short film Great Transitions: The Origin of Tetrapods. The film describes the discovery of Tiktaalik, a key fossil that illuminates the evolutionary history of four-legged animals.

The Origin of Tetrapods provides a first-hand account of the search for Tiktaalik, a creature with a mix of features common to fish and four-legged animals (tetrapods). Tiktaalik, along with a series of species that existed before and after, illuminates key evolutionary steps in the transition of life from water to land. The “Student Handout” probes students’ understanding of the key concepts addressed in the film. The “Educator Materials” document provides suggested pause points in the film with questions for students, background information, and detailed discussion points; a list of related resources and references; and an answer key for the “Student Handout.”