The Cretaceous predator that redefined our understanding of dinosaur diets and aquatic habits

Nature · Published 3 October 2026 Swipe more like this →

In short: Discovered by a plumber in a Surrey clay pit, Baryonyx walkeri shattered the image of theropods as strictly terrestrial hunters. With its crocodile-like snout and massive, hooked claws, this Early Cretaceous giant was the first dinosaur ever proven to be a fish-eater, bridging the gap between land and water.

When William J. Walker unearthed a large claw in the Smokejack Clay Pit in 1983, he triggered a paleontological sensation. Palaeontologists Alan J. Charig and Angela C. Milner later identified the specimen as a new genus, Baryonyx, meaning 'heavy claw'. The discovery was so significant that Charig dubbed it the 'find of the century' in Europe, as it provided the most complete spinosaurid skeleton ever recovered.

Baryonyx possessed a unique anatomy perfectly suited for its environment. Its long, narrow snout, featuring a terminal rosette of teeth, closely resembled that of a modern gharial, while its stomach contents—containing fish scales and juvenile iguanodontid bones—confirmed a diet that included both aquatic and terrestrial prey. Unlike most theropods, it featured a rudimentary secondary palate and a series of conical, finely serrated teeth, which were ideal for gripping slippery catches.

The creature's physical stature was equally imposing, with estimates suggesting a length of 7.5 to 10 metres and a weight between 1.2 and 2 metric tons. Its robust forelimbs, anchored by a 31-centimetre claw, suggest it used its arms as primary tools for processing prey. While debates persist regarding its exact classification and its relationship to other spinosaurids like Suchomimus, Baryonyx remains a landmark discovery that fundamentally altered our perspective on dinosaurian lifestyles.

The preparation of the holotype was a monumental task, requiring six years of meticulous work to extract the bones from hard siltstone. Today, the specimen serves as a critical reference point for researchers, though recent studies have re-evaluated many fossils previously attributed to the genus, highlighting the complexity of identifying spinosaurid remains across the Wealden Supergroup and beyond.

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