With a length of around 13 metres and a weight of eight tonnes, the Gigantosaurus was even more powerful than the Tyrannosaurus Rex. With small quills and large spots on its back, this dinosaur was quite a sight. The Gigantosaurus had three claws on each of its short front legs and fed on herbivores. Scientists suspect that the Gigantosaurus was able to run very fast thanks to its thin tail which it held upright.