Study of a previously unidentified dinosaur basicranium shows that it belongs to Triceratops sp., probably Triceratops horridus. The occipital condyle can be used to predict body size and skull size in extant reptiles, as illustrated here by study of Basiliscus vittatus and Alligator mississippiensis. Occipital condyle size is now known for 35 Triceratops specimens, and these can also be used t...

Since the recognition of fossils as remnants of once-living organisms by early polymaths such as Leonardo da Vinci and Nicholas Steno, paleontology has become the clearest window into the long history of life on Earth. During much of the nineteenth and twentieth centuries, paleontol-ogy was primarily an observational science, focused on the discovery, naming, and description of fossil plants an...