How Fast Were Dinosaurs?
Trying to estimate the speed of animals dead for more than 65 million years is difficult, but some generalizations are rather clear from the shape and size of dinosaur skeletons. For example, immense sauropods, such as Apatosaurus and Diplodocus with their massive bodies and columnar leg structure, were probably not fast runners other than in short bursts. Conversely, lighter and relatively long-limbed theropods, such as Velociraptor and ornithomimids (or "ostrich-mimic dinosaurs) were probably capable of running at high, sustained speeds.Absolute speeds for extinct animals have been estimated by using complex models in which the length of the stride (as measured from trails of fossil footprints called trackways) and leg length is compared to the same data measured in living animals. Such comparisons are complicated by the fact that it's often difficult to identify the exact kind of dinosaur that made a specific trackway, especially because fossil skeletons of dinosaurs are often rare or absent in rock layers that preserve fossil footprints.Like many aspects of extinct dinosaur behavior or biology, the speed of different dinosaurs have been subject to fantastic and speculative claims that are difficult to test rigorously with reliable scientific evidence. However, the available evidence and models suggest that, while larger dinosaurs may have been capable of running, they were predominately slow-footed and unable to attain the speeds of even a moderately fast human sprinter.This video is part of a series, "Dinosaurs Explained," produced by the American Museum of Natural History. In the series, Museum paleontologists answer the most frequently asked questions about dinosaurs.To watch the videos, go to www.amnh.org/explore/amnh-tv. Click on the "Dinosaurs Explained" Tab on the left side of the page. In the playlist, start with the first question and play each video consecutively for a mini-course in dinosaur fossils.