Acrocanthosaurus was the largest predator in all of Early Cretaceous North America. This giant was 36-40 feet long and weighed 3-5.5 tons. While a carcharodontosaur, Acrocanthosaurus had a sail like the spinosaur family, though it was more of a muscular ridge. This reconstruction is based on the taller than average spines that make up the sail on their backs. Acrocanthosaurus lived about 130 million years ago.