Paleontologists in Uruguay have discovered large, poorly preserved and incomplete skulls, as well as several associated bones, of ancient aquatic reptiles called mesosaurs. These new specimens suggest the existence of gigantism in mature mesosaurs reaching more than twice the size of previously described adults and type specimens. Mesosaurs are small to mid-sized aquatic to semiaquatic amniotes that lived in Gondwana during the Early Permian epoch....
