English: Acrocanthosaurus is a carcharodontosaurid dinosaur from the Early Cretaceous of what is now North America. Large theropod footprints discovered in Texas are theorized to have been made by Acrocanthosaurus. It had a long narrow skull, with low ridges rising from the nasal bones, running along each side of the snout from the back toward the eye. Acrocanthosaurus is best known for the tall neural spines on the vertebrae down the neck, back, and upper tail. These spines likely supported a ridge of muscle down its back. It was one of the largest theropods, reaching around 11.5 m in length and weighing up to 6.6 t.