Richard: Footprints are found in a variety of depositional environments, and it’s just like any other thing. For footprints, modern footprints, you have a human footprint and you walk on certain substrates like sand or a mud, firm sand, wet sand. You name it.

Ariel view of a fossil track site, an exposed rocky patch of ground with blue tarps strewn around it. Several people sit on the ground looking at the tracks. The camera slowly pans over the length of the site.

Lisa: That footprint is gonna look different.

Richard: It is. Sometimes it’s not gonna look like much at all. You’re not even going to be able to see toes.