Dilophosaurus holds a significant place in the history of life on Earth, representing one of the earliest large predatory dinosaurs of the Early Jurassic period. This slender, bipedal creature was a notable apex predator in its North American environment, reaching lengths of over 20 feet and weighing up to nearly 900 pounds. While popular culture has exaggerated some of its supposed features, understanding its true nature requires looking beyond fiction and directly at the fossil record.
The Definitive Answer: Dilophosaurus’s Diet
Dilophosaurus was unquestionably a carnivore, a classification firmly established by its placement within the Theropoda suborder of dinosaurs. The genus, Dilophosaurus wetherilli, lived approximately 193 million years ago, with primary fossil evidence discovered in the Kayenta Formation in Arizona. As the largest known land animal in North America during its time, it occupied a top position in the food web.
Its classification as a theropod places it in the group that includes all predatory dinosaurs, from the earliest small hunters to the later, massive tyrannosaurs. Earlier interpretations suggested a relatively weak bite, leading to debate among paleontologists regarding the extent of its hunting versus scavenging habits.
Newer research suggests that the animal was a more capable predator than previously thought, with stronger jaw muscles than earlier studies indicated. This modern view paints Dilophosaurus as an opportunistic feeder, ready to hunt large or small animals, or to scavenge carrion when available. Evidence also suggests it may have incorporated fish into its diet, supported by the discovery of its fossils in environments near water sources.
Physical Indicators of a Predatory Lifestyle
The anatomical structure of Dilophosaurus provides the clearest evidence of its carnivorous nature, demonstrating a toolkit built for capturing and processing flesh. Its skull was long and relatively narrow, a shape that contributed to earlier suggestions of a delicate jaw. A distinctive feature is a noticeable gap, or ‘kink,’ located between the premaxilla and the maxilla bones of the upper jaw.
This notch, known as a subnarial gap, was once thought to indicate a weak bite force. However, the teeth behind this gap were sharp, thin, and recurved, meaning they curved backward. This morphology was ideal for slicing flesh and preventing a struggling victim from escaping. Recent analysis suggests that its jaw was capable of absorbing the stress of struggling prey, and the teeth were serrated to shear through tissue.
The forelimbs and hindlimbs also support an active, predatory life, with strong legs suggesting it was a fast-moving, bipedal runner capable of pursuing prey. Its hands featured three functional fingers, with the first finger being short but strong and bearing a large claw, useful for grasping or restraining a victim. The distinct pair of thin, bony crests atop its head served as cranial ornaments, likely used for display, such as attracting mates or recognizing others of its own species.
Separating Fact from Fiction
The public’s perception of Dilophosaurus has been heavily influenced by its depiction in popular media, which introduced several dramatic but scientifically unfounded features. The most pervasive misconception is the ability to spit venom at its prey. There is no fossil evidence—such as specialized ducts, fangs, or venom glands—to support the idea that this dinosaur was venomous.
Another entirely fictional trait is the large, retractable neck frill, which the creature is shown to expand when attacking. This cowl-like structure is an invention for dramatic effect, likely inspired by modern frilled lizards, and is completely absent from the fossil record. The real animal was a formidable, slender predator defined by its unique double crests and slicing teeth, not by fictionalized toxic abilities or a terrifying, flaring neck display.