Acrocanthosaurus , meaning 'high-spined lizard') is a genus of theropod dinosaur Acrocanthosaurus is a bipedal carnivore. As the name suggests, it is best known for the high neural spines on many of its vertebrae, which supports a ridge of muscle over the animal's neck, back and hips. Acrocanthosaurus is one of the largest theropods, approaching 12 meters (40 ft) in length, and weighing up to 6.17 metric tons (6.8 short tons).