Ray Stanford: This part on my right was the part that was sticking above the ground when I made the discovery and I recognized immediately that we’re looking at a large footprint of a armored dinosaur, a Nodosaur. And, it was not until we excavated the dirt out of the back of it that we realized a baby dinosaur had stepped in it; and a lot of other activity was going on. Martin Lockley: We’re looking at the largest known slab that has mammal tracks on it from anywhere in the world. I know of about four or five sites in the whole age of dinosaurs that have mammal tracks and some of them only have one or two and here we’ve got approximately a hundred footprints on it. It’s amazing! Well this whole area here, is very, very, interesting because we have these nice five toed tracks, theirs actually a pair here. So we have a left and a right, and as mammals we have five fingers and five toes, and so these are our cretaceous ancestors you might say. For a comparison you could look at this track, it has three toes and that is just typical of a modern bird, or the ancestor of a modern bird, which was a small theropod dinosaur. This one here is very small, it’s the size of a squirrel track and has its toes going in this direction. Ray Stanford: I find this very exciting because of the kind of details we can see. And see how sharp these claws were. Martin Lockley: What's special about this track is that it is the largest mammal track on this surface and indeed it’s the largest mammal track known from the age of dinosaurs. During the age of dinosaurs we’ve traditionally regarded most mammals as the size of rodents, rats, and squirrels and so forth. It is very rare to find anything this big. I mean this was an animal that was maybe the size of a badger. This was a big animal by mammal standards from the age of dinosaurs. Ray Stanford: What excites me about this slab found at Goddard Space Flight Center, is that this shows us the actual life in action of all this incredible diversity. From the flying reptiles, to the large dinosaurs, to the very small or tiniest perhaps dinosaurs. And three, four, five types of mammals. In fact, it shows us not the dead but life is almost like a time machine. We can look across I guess, maybe two weeks of activity of animals and we can almost picture it unlike if we were just looking at bones. We see the interaction, how they pass in relationship to one another. So what we have here from Goddard, is looking deeply into ancient time on the Earth, and I think it's just tremendously exciting. (music) (music) (music) (music) (music)