Baryonyx

***Baryonyx*** (Name meaning: Heavy Claw) is a species of large, carnivorous dinosaur discovered in clay pits just south of Dorking, England. The species only known from a single; subadult; specimen, and because remains of its last meal were discovered fossilized in its ribcage; both remains of fish and an Iguanodon; it gave true clear indication of the spinosaurids diet as Generalist carnivores similiar to crocodilian species and large avians; different from previously thought as solely piscivores. It lived in the Barremian period of Early Cretaceous, around 125 million years ago.

## Description

*Baryonyx* estimated about 7.6 to 10 meters long (25 to 33 feet), and around 2.7 meters (9 feet) tall. It probably weighed in the region of 2 tons, but analysis of the bones suggests that the only known specimen was not even fully grown!

The fact that the skull and vertebra of *B. walkeri* holotype specimen (NHM R9951) do not appear to have fused suggests that the individual was not even fully grown, and the mature animal may have been much larger; as is the case for some other species of spinosaurids.

On the other hand, the specimen's fused sternum indicates that it may have been mature.

*Baryonyx* is a very unusual tetanuran. The design of its hips and pelvis suggests that it was bipedal for the purposes of walking from place to place. However, its forelimbs were absurdly large for a theropod, this has been speculated by some, that it being an indicator of the theropod spent at least some of its time on all fours.

Unlike dromaeosaurids, the creature had a long curved claw on the thumb of each hand, rather than on its hind legs. This claw measured at about 30.4 centimeters (12 inches).

The skeleton was not arranged exactly as it would have been in life (articulated), so the paleontologists reconstructing it placed them on the front feet because these legs were so powerful. The bone structure suggests a massive bulk of muscle ran down the sides of these front legs, and it therefore seems probable that the claws were placed here.

The long neck was fairly inflexible, and was not S-shaped as in many other theropods. The skull was set at an acute angle, not the 90° angle common in similar dinosaurs. The long jaw was distinctly crocodilian, and had 96 teeth, twice as many as its relatives. Sixty-four of the teeth were placed in the lower jaw (mandible), and 32 large ones in the upper (maxilla). The snout probably bore a small crest. The crocodile-like jaws and large number of finely serated teeth suggested to scientists that *Baryonyx* was a fish-eater. As confirmation, a number of scales and bones from the fish *Lepidotes* were also discovered in the body cavity.

It is speculated that *Baryonyx* would sit on a riverbank, resting on its powerful front legs, and then sweep fish from the river with its powerful striking claw. This is similar to the modern grizzly bear. The long but low stance and angled head support this theory.

Until the discovery of the closely-related *Suchomimus*, *Baryonyx* was the only known mostly piscivorous (fish-eating) dinosaur.

On the other hand, bones of an *Iguanodon* were also found in direct association with the *Baryonyx* skeleton. A definitive proof, that *Baryonyx*killed and/or scavenged any prey item it could find.

Even more fossil evidence shows the Portuguese/Iberian Baryonyx fossils are, also, found directly associated with Iguanodon teeth, and listed with other such associations as support for opportunistic feeding behaviour in spinosaurs

These fossils are even more clear proof directly pointing that Spinosauroids aren't obligate piscivores as previously thought. It was one of the biggest carnivores of its era; its only competitor was the *Neovenator*; a relative of the *Allosaurus*.