Perhaps the tallest animal that ever lived, Sauroposeidon was a true giant. These vegetarians reached over 100 feet in length and weighed as much as 70 tons. However, the most noteworthy quality of this dinosaur is it's extraordinary height. These sauropods were about 50-60 feet tall. With such a massive body, Sauroposeidon had few, if any, predators. Sauroposeidon lived in North America around 110-125 million years ago.