Argentinosaurus

Argentinosaurus is a huge sauropod dinosaur that lived in Argentina during the Middle Cretaceous period. It was 30 meters long and 70 tons weight.To date, researchers haven't found an entire skeleton, but what they have found--four-foot long vertebrae and five-foot-long tibiae--indicate that Argentinosaurus was a truly titanic sauropod (hence its classification in some circles as a titanosaur).

Interestingly, the remains of Argentinosaurus were dug up near the fossils of another huge dinosaur--the carnivorous theropod Giganotosaurus. This has led paleontologists (and TV producers) to speculate that packs of Giganotosaurus may have hunted down full-grown Argentinosaurus adults--a chase that would have been deadly for any smaller creatures that happened to get in the way! (By the way, paleontologists in India have uncovered the remains of a possible titanosaur, Bruhathkayosaurus, that may have been even bigger than Argentinosaurus; the trouble is, no one is exactly sure what type of dinosaur this was!)