But the staff is reassuring. That night, after a hearty camp dinner, we gather around the excavation site. Horner christened the great dinosaur Maiasaura , 'good mother lizard,' because of evidence of maternal behavior and has theorized that these dinosaurs were altricial, meaning they nurtured their young. The idea has been hotly debated in the scientific community, but no one disputes the fact that vast herds of maiasaurs trooped through here. When he tried to tamp the tent stakes into the ground, they kept hitting rocks.
Volunteers painstakingly work a bone bed in hopes of finding fragments of dinosaur fossils.
Even after the sun has set and stars are blazing across the big Montana sky, the dinosaur talk goes on. At that point, about 65 million years ago, something destroyed the mighty creatures that had dominated the Earth for more than a hundred million years . Scientists don't know what that something was, though there is some evidence that a meteor struck the Earth, sending up a cloud of dust that killed vegetation and the animals that fed on it. The key to that mystery, and all other paleontological puzzles, lies in the rock layers , and the next day geologist Anna Breuninger gives us a quick primer course in the geology of our site. In the Cretaceous period, this area was upper coastal plains lying at the edge of the newly forming Rocky Mountains.