Baryonyx

Baryonyx (meaning “heavy claw”) is a genus of large theropod dinosaur that lived during the Early Cretaceous period, approximately 130–125 million years ago. Fossils have been recovered primarily from the Wealden Group of southern England, with additional material reported from Spain and possibly other parts of Europe. The type species, Baryonychus walkeri, was described in 1986 following the discovery of a partial skeleton that included a distinctive large, curved claw on the first digit of each hand, which is the feature that inspired its name.

Baryonyx measured around 7.5–10 metres in length and is estimated to have weighed between one and two tonnes. Its anatomy combines several unusual traits: a long, narrow snout resembling that of a modern crocodile, numerous conical teeth with finely serrated edges, and a massive claw up to 13 centimetres long. These adaptations suggest a primarily piscivorous diet, supported by stomach contents that have yielded fish scales and bones, though it likely also captured smaller terrestrial prey and carrion. The combination of a crocodile-like snout and robust forelimbs indicates a versatile hunting strategy, possibly involving ambushes in water or along riverbanks.

Phylogenetically, Baryonyx belongs to the family Spinosauridae, a clade of theropods known for their semi-aquatic habits and elongated skulls. Within this group it is closely related to Spinosaurus and Suchomimus. The discovery of Baryonyx helped expand understanding of spinosaur diversity and reinforced the concept that some large theropods occupied ecological niches similar to those of modern crocodilians. Ongoing research continues to refine its classification and paleobiology.