Dinosaur gastroliths revisited

Abstract

Additional information on the alleged gastroliths in Early Cretaceous formations of the Western Interior has changed the writer's opinion from skepticism about a dinosaur causative agency to belief that it is a valid explanation. Concentrations of exotic rounded and polished stones have been found in close association with a number of skeletons. Aside from this, the best evidence is distribution of individual stones in environments where inorganic agencies seem improbable; distinctive individual stones have apparently been carried hundreds of kilometers. Gastroliths have value as quasi-guide fossils. From geographic and geologic associations it is suggested that various sauropods and perhaps the contemporary ornithopod, Tenontosaurus tilleti, were the chief stoneswallowers of the Early Cretaceous of the Western Interior.