The small, bird-like theropod dinosaur historically known as Troodon has fascinated paleontologists for decades. The dinosaur’s original name, meaning “wounding tooth,” comes from one of the first fossils discovered, a single, unusual tooth. While the genus name Troodon is still used commonly, much of the skeletal material previously assigned to it has been reclassified to related species like Stenonychosaurus inequalis. Determining what this quick, extinct creature ate requires scientists to analyze indirect evidence from its fossilized remains and compare them to living animals that roamed North America during the Late Cretaceous period.
Anatomical Clues to Troodon Diet
The teeth of Troodon and its relatives offer the strongest physical evidence regarding their feeding habits. Unlike the blade-like teeth of large, purely carnivorous theropods, Troodon’s teeth bear large, prominent serrations known as denticles. These denticles are morphologically similar to those found on the teeth of some herbivorous reptiles, suggesting a capacity to process plant material. Wear facets on the sides of the teeth further indicate a chewing or shredding motion, which is not typical of dinosaurs that simply slice and swallow flesh.
The structure of the jaw also supports a varied diet. The lower jaws meet in a broad, U-shaped symphysis, similar to the jaw structure of the modern iguana. Iguanas are adapted to a plant-eating lifestyle, reinforcing the possibility that the dinosaur could manage vegetation. However, the wear patterns are inconsistent with chewing hard items like bone or tough plant fiber, suggesting the diet likely consisted of soft foods.
The Omnivore Hypothesis
The unique dental features and jaw mechanics have led to the scientific consensus that Troodon was an opportunistic omnivore, consuming both animals and plants. Specific prey items likely included small mammals, lizards, insects, and the eggs and hatchlings of other dinosaurs. Its ability to process softer foods suggests it may have also scavenged carcasses.
Recent biogeochemical studies support this hypothesis by analyzing elemental ratios in the tooth enamel of troodontids. Ratios of Strontium to Calcium (Sr/Ca) and Barium to Calcium (Ba/Ca) in the enamel of troodontid fossils fall between those of megaherbivores and pure carnivores. These findings strongly suggest a mixed-feeding diet, or even a diet that was plant-dominant for a theropod. The plant portion of the diet would have included soft vegetation such as seeds, fruits, and possibly tubers.
This adaptability would have been advantageous, especially in environments where food resources fluctuated. The dinosaur’s diet was likely determined by what was most readily available in its immediate habitat, contrasting with the strict carnivory of its close relatives, the dromaeosaurids.
Hunting Strategies and Sensory Adaptations
To successfully acquire a varied diet, Troodon possessed several specialized sensory and physical adaptations. This dinosaur had one of the largest brains relative to its body size of any known dinosaur, giving it a high Encephalization Quotient (EQ). This relatively large brain suggests a capacity for complex behaviors, including sophisticated hunting and problem-solving skills necessary for exploiting diverse food sources.
The structure of the skull shows that the eyes were large and positioned forward, granting it excellent binocular or stereoscopic vision. This depth perception would have been crucial for accurately judging distances when stalking or grasping small, quick-moving prey. The large eye sockets suggest that Troodon may have been active primarily at night or during twilight hours.
Its slender, long back legs suggest that Troodon was built for speed and agility, allowing it to rapidly pursue and capture small animals. The hands and feet were also adapted for grasping, with a retractable, hooked claw on the second toe that could have been used to secure struggling prey.