Baryonyx walkeri, the first-discovered fish-eating dinosaur, had a crocodile-like snout and finely serrated, conical teeth. In 1983, William Walker, an amateur collector, found the fossilised claw bone of B. walkeri in a Surrey clay pit, encased in 125 million-year-old rocks from the Early Cretaceous Period. In doing so, he had made the most important European dinosaur discovery in a century. A team from the Natural History Museum later recovered about 65 percent of the skeleton. Baryonyx means heavy claw, and the dinosaur's thumb, covered in a sharp and horny sheath, was probably used to spear fish or rip open carcasses. The teeth helped the dinosaur grip its slippery prey, and set-back nostrils allowed it to hold its snout underwater while still being able to breathe. Baryonyx belongs to a specialist group of theropods called spinosaurs, which had distinctive, elongated spines and long, narrow skulls.