Gastonia, a mid-sized ankylosaur, is one of the spiniest dinosaurs ever. This herbivore was around 10-13 feet long and weighed over 1,000 pounds. The spikes that covered it's body could be up to a foot long. It's tail was designed like a chainsaw and was a deadly weapon that it used against predators like Utahraptor and Acrocanthosaurus. Gastonia lived in North America about 115 million years ago.