Cards &



From a British clay pit

Baryonyx, or simply “heavy claw” among friends, waded through the shallow areas of the Cretaceous period like a bipedal crocodile, hunting fish with its 30-centimeter-long thumb claw. Its mouth, resembling that of a crocodile, and its cone-shaped teeth were well-suited for being a true piscivore (fish-eater).

However, a Baryonyx found in England actually had remains of an Iguanodon in its stomach, so other dinosaurs couldn’t consider themselves safe when the “heavy claw” passed by. Baryonyx became known after a British plumber named William Walker discovered a spectacular claw while fossil hunting in a clay pit one afternoon in 1983. He took the claw home, but a piece of the tip was missing. William returned to the clay pit and found the spot where he had initially found the claw. After an hour of searching, he found the missing piece! William Walker’s son-in-law took the claw to the Natural History Museum in London and showed it to the researchers. They realized it was something extraordinary, and two paleontologists studied the claw and determined it belonged to a dinosaur.

The museum’s paleontologists immediately went to the clay pit and eventually discovered the entire skeleton. William donated the claw to the museum, and stories like this are not uncommon at all. Many of the most amazing fossils have been found by ordinary, curious plumbers, accountants, and schoolchildren.

Possibly over 10 meters long as an adult

Around 1.5 tons

Early Cretaceous period (130 – 125 million years ago)


Discovery sites
United Kingdom, Spain, and Portugal