No known true dinosaurs climbed or lived in trees. At one time, the foot bones of the Hypsilophodon, a small herbivorous ornithopod, were thought to have the big toe facing opposite to the other toes, similar to a bird’s foot. Scientists speculated, based on this erroneous assumption, that this dinosaur lived in trees, perching on branches in a way similar to today’s Australian tree kangaroo. When the true foot bone structure was discovered, however, it was realized that Hypsilophodon was a swift land runner, using its speed and agility to escape predators and not to live in trees.

There are some scientists who speculate that some of the feathered dinosaurs, such as the Microraptor from China, may have glided from tree to tree or used its extended toe to grasp tree branches. The animal may have adapted this way to escape predators or even to find a better meal. But more evidence needs to be found before researchers can say dinosaurs lived or climbed in trees.