Baryonyx, a distinctive theropod dinosaur, roamed the floodplains and swamps of Early Cretaceous Europe approximately 130 to 125 million years ago. This large carnivore measured between 7.5 and 10 meters (25 to 33 feet) in length and weighed an estimated 1.2 to 2 tons. It possessed unique physical characteristics that set it apart from many other large predatory dinosaurs of its time. Its name, “heavy claw,” directly references its most prominent feature: an unusually large claw on its thumb.
Primary Dietary Habits
Scientists believe Baryonyx primarily consumed fish, a dietary habit known as piscivory, based on its specialized anatomy. Its elongated, low, and narrow snout, often compared to that of a modern gharial, was well-suited for catching aquatic prey. The tip of its snout featured a distinctive “rosette” shape, and its jaws contained around 96 conical, finely serrated teeth, which were round in cross-section and effective for gripping slippery fish. The large, hooked claw on its thumb, measuring up to 35 centimeters (14 inches) long, played a significant role in its hunting strategy, likely used to gaff or hook fish out of the water. The combination of its crocodile-like jaws, specialized teeth, and powerful thumb claw suggests a highly adapted predator that spent considerable time near water sources, efficiently capturing its primary food source.
Fossil Clues to its Diet
Direct fossil evidence provides clear insights into the Baryonyx’s diet. The most compelling discovery occurred within the stomach region of the original Baryonyx specimen, found in Surrey, England, where paleontologists identified acid-etched scales and teeth belonging to the common fish Scheenstia mantelli. This finding was groundbreaking, as it offered the first direct proof of piscivory in a theropod dinosaur. The unique structure of the Baryonyx skull further supports a fish-eating lifestyle, with its narrow snout, downturned tip, and notch aiding in grasping slippery prey. Studies on its skull biomechanics indicate similarities to modern fish-eating crocodilians, suggesting jaws adapted for quick strikes and holding prey, and a secondary palate reinforced its snout for aquatic captures.
Broader Eating Habits
While primarily a fish-eater, evidence suggests Baryonyx did not exclusively consume aquatic prey. The stomach contents of the same holotype specimen also included abraded bones of a juvenile Iguanodon. This indicates that Baryonyx likely had a broader diet, potentially scavenging on carrion or occasionally preying on smaller terrestrial animals. Like many predators, Baryonyx was probably an opportunistic feeder, exploiting available food sources within its environment. Although the Iguanodon bone points to a more varied diet, the overwhelming anatomical and direct fossil evidence still strongly supports fish as its main sustenance. This flexibility in diet would have allowed Baryonyx to thrive in its wetland habitats.