Evolution Forget T. Rex: Long-Necked Dinosaurs Ruled the Planet The long-necked dinosaurs known as sauropods, once seen as icons of extinction, thrived for millions of years around the world By Kristina A. Curry Rogers and Michael D. D*amp*apos;Emic THIS IS A PREVIEW. Buy this digital issue to access the full article. Already purchased this issue? Sign In Apatosaurus, the proper scientific name for the famous Brontosaurus, exhibits the classic sauropod silhouette: a long spinal column, tapered on both ends, topped with a small-brained skull and balanced on four pillarlike legs. Over the course of their long reign, sauropods evolved various body sizes and different teeth and snout shapes, but their basic architecture stayed the same. Christopher Griffith Ever since fossils of the behemoth, long-necked dinosaurs known as sauropods surfaced in England more than 170 years ago, they have awed and confused scientists. Even when the great English anatomist Sir Richard Owen recognized in 1842 that dinosaurs constituted a group of their own, apart from reptiles, he excluded the gigantic bones later classified as sauropods. Instead he interpreted them as belonging to a type of aquatic crocodile, which he had named Cetiosaurus, or “whale lizard,” for the enormous size of its bones. Nearly 30 years later, in 1871, University of Oxford geologist John Phillips would report the discovery of a Cetiosaurus skeleton sufficiently complete to reveal that, far from being an aquatic crocodile, the animal spent at least some of its time on land. Phillips's assessment caused considerable consternation among paleontologists for decades—they just could not conceive how such a massive animal could support its weight on land. Because sauropods were perceived as animals without a place, unsuited for land or sea, they came to be seen as unwieldy, overgrown, archaic herbivores fated for rapid extinction or, at least, marginalization by more “advanced” dinosaurs. As recently as 1991, scientists argued that sauropods were far from the apex of dinosaur success and only flourished in the absence of more specialized plant-eating dinosaurs. In this view, these giants of the Jurassic period, between about 200 million and 145 million years ago, gave way to bigger-brained, better-adapted herbivores in the Cretaceous, between some 145 million and 66 million years ago, such as the duck-billed hadrosaurs and horned ceratopsians, which outcompeted the sauropods and pushed them to the fringe. THIS IS A PREVIEW. Buy this digital issue to access the full article. Already purchased this issue? Sign In Buy Digital Issue $9.99 Add To Cart You May Also Like Scientific American Single Issue Evolution: What Makes Us Human Dinosaurs and Other Monsters Our Ever Changing Earth ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.