Genus: Baryonyx CHARIG & MILNER, 1986
Etymology: Greek, barys “heavy, strong”, and onyx “talon, claw”, Heavy claw.

Species: walkeri CHARIG & MILNER, 1986
Etymology: In honor of Mr. William J. Walker, who found the first indication of the skeleton, namely the large claw bone.

Holotype: BMNH Palaeo Dept. R. 9951

Locality: Claypit at Smokejacks Brickworks (Ockley Brick Company Limited), Wallis Wood, Ockley, near Dorking, Surrey County, England, Southern United Kingdom.

Horizon: Weald Clay, Upper Wealden.

Biostratigraphy:

Age: Near the base of the Barremian Stage, Lower Neocomian Subepoch, Middle Early Cretaceous Epoch, Early Cretaceous.

Material: Conjoined premaxillae, front of left maxilla, conjoined nasals, lachrymal and parts of adjacent bones, frontals, anterior end of braincase, occiput, left dentary, some post-dentary bones of the lower jaw, teeth in both jaws and in isolation, axis, most of the other cervical vertebrae, some dorsal vertebrae, one caudal vertebra, cervical rib, dorsal ribs, gastralia, chevrons, both scapulae, both coracoids, possible clavicle, both humeri, phalanges of manus including ungual (one of them, not certainly from manus, extremely large), pieces of ilia and pubes, ischium, proximal end of left femur and distal end of right, left fibula lacking distal end, right calcanium, distal ends of metatarsals, phalanges, of pes including unguals, various unidentified pieces, suspected gastroliths.