Brachiosaurs were gigantic dinosaurs that roamed what is now Europe, Africa, and North America 150 million years ago, reaching heights of more than 40 feet and lengths of more than 80 feet. The most complete fossil skeletons found to date are of brachiosaurs that were not fully grown, so it is possible that they were even larger at maturity.
Brachiosaurus means “arm lizard”, a reference to the fact that their front legs were longer than their hind legs. This is unusual among sauropod dinosaurs and probably allowed them to browse for food high up in trees, where other dinosaurs could not reach. Brachiosaurs and other sauropods had a challenging diet by the standards of modern herbivores. Grasses and flowering plants had not yet evolved, so they ate what lived at the time, including conifers, ferns, cycads, and ginkgo trees. A single brachiosaur ate over 800 pounds of plant material each day, swallowing it whole and letting it digest slowly in its gut.
