Amateur fossil hunter William Walker found a large claw in Surrey, England in 1983. After it was brought to the attention of the Natural History Museum of London, a group of paleontologists traveled to the site to locate the reset of the skeleton. The discovery was eventually named Baryonyx in 1986. It was, at the time, the first theropod dinosaur discovered from the Early Cretaceous Period.
Baryonyx belonged to the family Spinosauridae, which includes the giant sail-backed Spinosaurus, and Baryonyx’s closest known relative, Suchomimus. In fact, for a time Suchomimus was believed to be a species of Baryonyx, though they are now generally recognized as distinct, but very closely related.