Jim McMahon/Mapman®

It’s as close as we may ever get to a snapshot of Earth before the Ice Age. Look carefully at this 8-foot by 3-foot slab of sand­stone, and you’ll see the foot­prints of dinosaurs, flying reptiles, and mammals that lived and interacted more than 100 million years ago in what is now Maryland.

The once-soft mud eventually hardened, preserving more than 70 footprints. Unearthed on the grounds of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the slab is now providing insight into a time when North America teemed with these beasts. Because no prints overlap, scientists think it could be the most accurate record ever found of prehistoric species crossing paths within a few days—or hours—of one another. As Ray Stanford, the amateur paleontologist who found the rock, told The Washington Post: “One could literally make a movie about everything going on in this slab.”

It is as close as we may ever get to a snapshot of Earth before the Ice Age. Look carefully at this 8-foot by 3-foot slab of sandstone. You will see the footprints of dinosaurs, flying reptiles, and mammals. Those creatures interacted more than 100 million years ago. They lived in what is now Maryland.

The footprints were made in what then was soft mud. When that mud hardened, it preserved more than 70 footprints. The sandstone slab was unearthed on the grounds of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. It now is providing insight into a time when North America teemed with those beasts. No prints overlap. For that reason, scientists think it could be the most accurate record ever found of prehistoric species crossing paths. The animals likely crossed paths within a few days—or even hours. Ray Stanford is the amateur paleontologist who found the rock. As he told The Washington Post, “One could literally make a movie about everything going on in this slab.”