brontosaurus

The size of the basin at the Colorado track site suggests that one of the brontosaurs that strode across the area was the culprit, says McCarville.

Over 150 species of sauropods, the long-necked, long-tailed four-footed herbivores informally called brontosaurs, have been described.

And the Jurassic display had brontosaurs and stegosaurs and allosaurs.

"If one looks at it that way, it looks as though brontosaurs were about as athletic as elephants," Alexander says.