One of the great themes in palaeobiology is the water-land transition, or how and when the ancestors of today's four-legged terrestrial animals moved to land. Lines of questioning have included understanding the anatomy and biomechanics of the axial skeleton- head and vertebrae (focusing on biting and swallowing) and the appendicular skeleton (focusing on how the earliest tetrapods walked or swam). Our picture of this story has drastically changed in the last three decades, as new fossils have filled in crucial gaps in the tetrapod evolutionary tree. This changing picture really came to the fore with the work of the late Professor Jenny clack, who's work at Cambridge in early tetrapods from Greenland and elsewhere brought the water land question back in fashion. Joining us to discuss Jenny Clack's Legacy in this episode are Prof. Mike Coates and Ben Otoo both of the University of Chicago.