You may laugh at its tiny, almost useless arms or find its size and weight not too impressive compared with other carnivores of its time, but the Aucasaurus was still a fearsome beast – particularly when hunting in packs. Together, a group of these dinosaurs could bring down much larger prey. Discovered in the Patagonia region of Argentina in 1999, the Aucasaurus didn’t have much to fear (except natural disasters, of course.)

Nevertheless, the only specimen of the species that was discovered showed damage to the skull, suggesting that this dinosaur was involved in a fight with another dinosaur prior to its death. That, or the aucasaurus refused to pay for something and got into trouble. You know what they say: short arms, deep pockets.