Hadrosaurs on the Run

During the 1970's Ostrom took a short break from birds and Deinonychus to investigate some trackways discovered near the town of Holyoke in Massachusetts. Holyoke is near the middle of Massachusetts in the Appalachian Mountains and only a few hours north of Yale. The nearby Ostrom and Yale were the logical first calls for someone in Massachusetts to make. The trackway that was discovered was approximately 150 feet by 60 feet and covered by nearly 140 foot prints with three toes. The impressions measured between 2.5 inches to 13.8 inches long. The tracks belonged to small theropods like Grallator. Ostrom studied their feeding and moving habits and also studied trackways of herbivores to determine how they moved. The interactions of the tracks of predator and prey appeared to have indicated that the larger herbivores moved in larger herd for protection while the predators moved in small groups or singly. The trackways near Holyoke were oriented in parallel pathways, indicating that the small theropods must have been traveling together in search of prey items. The ichnofossil (trace fossils such as trackways) and inferred behavioral studies of Ostrom are less well known because they were eclipsed by his work on Deinonychus and warm-bloodedness as well as his work on bird-dinosaur connections. However, his 1972 article entitled Were some dinosaurs gregarious? was a very important piece of the herding and predating behaviors of dinosaurs that had not been highly explored at that time. Thankfully they have been explored in much depth since then, but this article was very influential in these studies.