This week our understanding of when humans first inhabited the North American continent has been turned on its head … by a set of c.22,000 year old footprints. In this episode, hear how footprints can form crucial evidence for populations of prehistoric people and animals, and how now extinct famous megafauna such as mammoths and giant sloths once interacted with early humans. To reveal all about this ground breaking new discovery, Tristan was joined by Bournemouth University's Dr Sally Reynolds.

Sally's Twitter - @SallyR_ISLHE

Tristan's Instagram / Twitter - @ancientstristan