Baryonyx walkeri

Baryonyx walkeri is a spinosaurid theropod from the Early Cretaceous (about 125 million years ago), discovered in England in 1983 and described in 1986. The discovery of its skeleton—one of the most complete among spinosaurids—has allowed for a precise reconstruction of its anatomy and a better understanding of the evolution of this specialized lineage. With an estimated length of 7.5 to 10 meters and a weight of 1.2 to 1.7 tons , Baryonyx combines typical theropod traits with clear adaptations for a semi-aquatic, piscivorous lifestyle.

Its long, narrow skull had a distinctive shape similar to that of modern gharials. It measured around 90 cm and featured an elongated snout with a premaxillary rosette, an expansion at the tip of the jaws where larger teeth were located, ideal for grasping slippery prey. Along its jaws, it possessed approximately 96 teeth , more numerous and finer than those of other theropods, conical in shape and barely serrated, traits associated with catching fish. The surface of the palate and the arrangement of the teeth suggest that it could close its jaw not by cutting, but by gripping firmly.

The neck was relatively long and robust, with cervical vertebrae that combined lightness and strength, necessary for rapid forward movements when capturing prey. The vertebral structure exhibits internal cavities (moderate pneumatization), a feature shared with other spinosaurids.

Its spine and ribs indicate a deep, muscular torso. The axial skeleton of Baryonyx does not yet show the developed sail seen in Spinosaurus , suggesting that this feature evolved later within the group. However, its broad ribcage indicates a strong animal, possibly capable of partial submersion.

One of the animal's most distinctive features is its forelimbs , exceptionally robust compared to other theropods. The most striking bone is the first digit , which boasts an enormous curved claw up to 31 cm long , one of the largest in any known theropod. This claw, combined with powerful arms, could have been used to tear apart large fish, capture prey from the shore, or manipulate carcasses.

The hind legs , although strong, were somewhat shorter than those of other theropods of similar size, consistent with a partially aquatic lifestyle. Its three functional toes ended in straight, relatively short claws, well-suited for moving across soft or muddy terrain near bodies of water.

The tail was long and muscular, probably flexible, and recent studies in closely related spinosaurids suggest that this group may have used the tail to swim by means of lateral movements, although in Baryonyx this adaptation was not as developed as in its Late Cretaceous relatives.

The preserved stomach contents—fish scales and bone fragments possibly from an iguanodontid—confirm that Baryonyx walkeri was an opportunistic predator , primarily piscivorous but capable of hunting or scavenging terrestrial prey. This evidence, combined with its cranial and appendicular morphology, positions it as one of the earliest spinosaurids clearly adapted to riparian environments.

Approximate measurements of the Baryonyx:

• 1:35 Scale - Two-piece assembly kit
• Length 278 mm
• Height 81mm
• Width 49 mm
• Snout-tail length 278 mm

• 1:20 Scale - Two-piece assembly kit
• Length 463 mm
• Height 141 mm
• Width 86 mm
• Snout-tail length 487 mm