 Tall spined vertebrae from the Early Cretaceous of England were once considered to be very similar to those of Acrocanthosaurus , and in 1988 Gregory S. Paul named them as a second species of the genus , A. altispinax . These bones were originally assigned to Altispinax , an English theropod otherwise known only from teeth , and this assignment led to at least one author proposing that Altispinax itself was a synonym of Acrocanthosaurus . These vertebrae were later assigned to the new genus Becklespinax , separate from both Acrocanthosaurus and Altispinax . 
