In 1964, scientist Alick Walker decided these fossils were too different from Altispinax, as it lacked the long vertebral spines, and named a new genus, Metriacanthosaurus.[4] The generic name is derived from Greek metrikos, "moderate", and akantha, "spine". Metriacanthosaurus thus gets its name from its vertebrae, which are taller than typical carnosaurs, like Allosaurus, but lower than other high-spined dinosaurs like Acrocanthosaurus.