Elmer S. Riggs Riggs' assistant, H. William Menke, found the first known skeleton of the giant sauropod dinosaur "Brachiosaurus altithorax" from near Grand Junction, Colorado. At the end of the 1900 field season Riggs' found a specimen of "Apatosaurus" near Fruita, a few miles from the Brachiosaurus site. This specimen was excavated during the 1901 field season, and was put on display in 1908 at the Field Museum. From these specimens he named "Brachiosaurus" and Brachiosauridae, and presented evidence that "Apatosaurus" and "Brontosaurus" were the same genus of dinosaur. He also proposed that sauropods were terrestrial animals, based on their limb structure, but
Dinosaur Footprints Reservation four distinct types of two-legged dinosaur, are present in the sandstone outcrops. Additional fossils that have been found at the site or nearby include invertebrate burrows, fish, and plants (including charcoalified logs and leaves). The parallel orientation of many of the dinosaur trackways was among the first lines of evidence used to support the novel theory that dinosaurs traveled in packs or groups. As the name implies, fossil footprints are this park's main attraction. They were formed during the Early Jurassic period (approximately 200 million years ago) when what is now the Connecticut River Valley was a subtropical region filled