Spinosaurus may be the larges Theropod to ever stalk the Prehistoric Americas and believed to be even larger than T-Rex. Recently (late it was determined to be the first and only known aquatic dinosaur.
Amargasaurus, a Sauropod dinosaur from the early Cretaceous Period (around 130 million years ago). Amargasaurus was small for a Sauropod and featured two rows of spines down its neck and back. Photo taken in Victoria Museum, Melbourne, Australia.