 At the time of its discovery , Acrocanthosaurus and most other large theropods were known from only fragmentary remains , leading to highly variable classifications for this genus . J. Willis Stovall and Wann Langston Jr. first assigned it to the " <unk> " , the equivalent of Allosauridae , but it was transferred to the taxonomic wastebasket Megalosauridae by Alfred Sherwood Romer in 1956 . To other authors , the long spines on its vertebrae suggested a relationship with Spinosaurus . This interpretation of Acrocanthosaurus as a spinosaurid persisted into the 1980s , and was repeated in the semi @-@ technical dinosaur books of the time . 
