Fossils found in Argentina of a ferocious dinosaur with a huge head covered in bumps and crests reminiscent of a gargoyle are providing insight into the evolution of some of Earth's biggest predatory dinosaurs including a curious trend toward puny arms. Scientists said on Thursday they discovered in northern Patagonia extensive skeletal remains of a previously unknown species called Meraxes gigas, including one of the most complete skulls of a large meat-eating dinosaur ever unearthed. All meat-eating dinosaurs belonged to a bipedal assemblage called theropods.