Partial skeletons of Acrocanthosaurus was first discovered in Oklahoma in the early 1940s, and named in 1950. Because a lot of the bones were missing, we weren’t sure exactly what Acroacanthosaurus looked like. In the 1990s, much more complete skeletons were discovered, providing more information on the unusual spines on the backbone, and allowing us to understand how the front limbs were used for hunting.
The vertebrae of the back of Acroacanthosaurus have very tall spines along the backbone that served as attachment points for large back muscles, much like a modern bison. These muscles helped to support the large head, and stabilized the large body and tail. You can see evidence of this in the ‘humped’ back of our Acrocanthosaurus toy model.