Lisa: Little burrows all over the place.

A large chunk of rock lays by the roadside. Lisa points to tiny bumps on its surface that are barely visible.

Richard: So those little tiny bumps on the surface or natural casts of invertebrate traces. So everything here is upside down the slab would have been oriented completely the other way, flipped over. That’s always something to keep in mind. It could have just as easily fallen track-side down.

Lisa: Yeah, then we would see nothing.

Richard: We would see nothing.