 The famous Glen Rose trackway on display in New York City includes theropod footprints belonging to several individuals which moved in the same direction as up to twelve sauropod dinosaurs . The theropod prints are sometimes found on top of the sauropod footprints , indicating that they were formed later . This has been put forth as evidence that a small pack of Acrocanthosaurus was stalking a herd of sauropods . While interesting and plausible , this hypothesis is difficult to prove and other explanations exist . For example , several solitary theropods may have moved through in the same direction at different times after the sauropods had passed , creating the appearance of a pack stalking its prey . The same can be said for the purported " herd " of sauropods , who also may or may not have been moving as a group . At a point where it crosses the path of one of the sauropods , one of the theropod trackways is missing a footprint , which has been cited as evidence of an attack . However , other scientists doubt the validity of this interpretation because the sauropod did not change gait , as would be expected if a large predator were hanging onto its side . 
