Period: Early Cretaceous

Order, Suborder, Family: Saurischia, Theropoda, Spinosauridae

Location: Europe (England), Africa (Niger)

Length: 31 feet (9.4 meters)

Baryonyx was found in 1983 by an amateur fossil collector in Surrey, England. He discovered a large claw that was nearly a foot long, and the animal was named for this fossil. Its name means "heavy claw." Paleontologists from the British Museum of Natural History went to the clay pit where the first fossil was found, and they discovered almost all of the skeleton. At first, scientists thought Baryonyx was unique and should be placed in its own family, the Baryonychidae. Now it seems that it is related to Spinosaurus, and so it is placed in the family Spinosauridae. Baryonyx is the most complete theropod dinosaur skeleton ever found in England.

The body and back legs of Baryonyx were much like those of other theropods, but not much else was the same. Unlike most theropods, its arms were long and heavily built. Also, the claws of the hands, especially the claw of the inside finger, were very heavily built. The length and robustness of the arm may mean that Baryonyx walked on all four limbs some of the time. If true, this is the only known theropod that did so.

The skull was more surprising than the arms. Most theropods had skulls that were a little longer than they were high, and they usually had 16 teeth in each side of the jaw. Baryonyx, however, had a very long, low skull. The lower jaw was slender and had 32 teeth. While most theropods had a "U" or "V" shaped snout (when viewed from above or below), the snout of Baryonyx was spoon-shaped. The shape of the snout and the very small serrations on the teeth were more like a fish-eating crocodile than most dinosaurs. Another strange feature of Baryonyx is that the nasal openings were behind the snout, rather than near its tip as in other theropods. Baryonyx also had a long neck, unlike most other large, meat-eating dinosaurs. From these features, scientists think Baryonyx probably was a fish-eater. It may have wandered along river banks, stretching its long neck out over the water and using its large claws to catch fish that swam by.

In several ways, Baryonyx was similar to primitive Early Jurassic dinosaurs such as Dilophosaurus. When all the bones of this unusual dinosaur are ready to be studied (it takes several years to prepare a large dinosaur), they will show more about its life and ancestry.