As is the case with many fossil vertebrates discovered by 19th century paleontologists, the taxonomy of Protosphyraena has had a confusing history. Fossil pectoral spines belonging to this taxon were first recognized in 1822, from chalk deposits in England, by Gideon Mantell, the physician and geologist who also discovered the dinosaur Iguanodon. In 1857, the fish was named Protosphyraena ferox by the renowned American naturalist and paleontologist, Joseph Leidy, based on Mantell's English finds. Earlier, Leidy had published an illustration of a Protosphyraena tooth from the Cretaceous-aged Navesink Formation of New Jersey (Maastrichtian), but mistakenly identified is as having come from a dinosaur. During the 1870s, B. F. Mudge, a fossil collector supplying material to rival paleontologis