Below: Giganotosaurus carolinii has been regarded as the largest known carnivore to roam the earth - a plaudit since taken by Spinosaurus. Amateur collector Ruben Carolini discovered the fossilized bones of this mighty meat-eater in Patagonie, Argentina in 1993, and a subsequent excavation unearthed a skull that was larger than any existing Tyrannosaurus. The reconstructed skeleton of this theropod is about 70% complete. Parts of a larger specimen have since been found, and indicate it was 8-10% greater in size.