Dilophosaurus | Double-Crested Predator of the Early Jurassic (2024)

The Early Jurassic Period was home to many intriguing dinosaurs, but one that stands out is Dilophosaurus. Known for the distinctive row of parallel crests that adorned its skull, this dinosaur has captured the interest of paleontologists and dinosaur enthusiasts alike. First discovered in the 1940’s, Dilophosaurus roamed the earth approximately 193 million years ago, a time when the world was very different from today. This article delves into the life and times of this fascinating creature, exploring its origins, physical characteristics, and the environment it inhabited.

Dilophosaurus, meaning “Double-Crested Lizard,” derives its name from the Greek words for “two” (di), “crest” (lophos), and “lizard” (sauros). This carnivorous dinosaur is best known for the pair of crests that adorned its head, a feature that has led to much speculation about their purpose. Were they for display, thermoregulation, or something else? As we uncover the details of Dilophosaurus’ life, we will also look at its contemporaries, providing a broader picture of the ecosystem it lived in.

Dilophosaurus Key Facts

Dilophosaurus Origins, Taxonomy and Timeline

The name Dilophosaurus, meaning “Double-Crested Lizard,” perfectly encapsulates one of the most distinctive features of this dinosaur: the pair of parallel crests on its head. The etymology of the name is rooted in Greek, with “di” translating to “two,” “lophos” to “crest,” and “sauros” to “lizard.” These crests have fascinated scientists and enthusiasts alike, leading to various hypotheses about their function, from species recognition to sexual selection or even thermoregulation.

Taxonomically, Dilophosaurus was an early member of the large clade of dinosaurs called Theropoda. Theropod dinosaurs, named for their distinctive three-toed foot morphology, sported a number of adaptations – such as razor sharp teeth and claws, elongated hind limbs, and bone-lightening air sacs – that contributed to their agility and predatory lifestyle. The type species, Dilophosaurus wetherilli, is the only species within this genus. Although no subspecies of Dilophosaurus have been identified, it is sometimes grouped with the southern African genus Dracovenator within the Dilophosauridae clade, highlighting the wide-ranging success of these early mega-carnivores.

Dilophosaurus lived during the Early Jurassic Period, specifically from the Sinemurian to the top of the Pliensbachian Epochs, approximately 199.3 to 182.7 million years ago. This era was a time of significant geological and climatic changes, with the supercontinent Pangaea beginning to break apart. The timeline of Dilophosaurus places it among the earliest large theropods, providing crucial insights into the evolution of later, more well-known carnivorous dinosaurs like Allosaurus and Tyrannosaurus rex.

Listen to Pronunciation

To listen to the correct pronunciation of this dino’s name, check out this video.

Discovery & Fossil Evidence

In the summer of 1942, paleontologist Charles Camp led a UCMP field party to Navajo County, northern Arizona, in search of fossil vertebrates. Guided by Navajo tribe member Jesse Williams, who had previously discovered the first bones in 1940, the team explored the Kayenta Formation near Tuba City. They found three dinosaur skeletons in purplish shale, arranged in a triangle. The first skeleton was nearly complete, the second was very eroded but included crucial parts like the front of the skull and an articulated hand, and the third was mostly eroded fragments.

Samuel P. Welles provided a preliminary description of this material in 1954, naming the dinosaur as a new species of the historic British genus Megalosaurus – M. wetherilli. The specific name honored John Wetherill, a Navajo councilor who Welles described as an “explorer, friend of scientists, and trusted trader”. However, being the first dinosaur ever named, Megalosaurus had by this point become something of a “waste-basket taxon” (a genus used to group material of vaguely defined similarities) and it wasn’t long before differences were noted between the new dinosaur and the former.

Near complete second skeleton

The major turning point came in 1964 when Welles returned to explore the Kayenta Formation and discovered a new nearly-complete skeleton of the same species. This individual (UCMP 77270), which was larger than the holotype, inspired Welles to more fully compare the American fossils to the European theropod. Realizing they were in fact different taxa (not to mention separated by about 20 million years), Welles renamed the Kayenta theropod Dilophosaurus.

The information preserved by the Dilophosaurus fossils is relatively good, with several specimens showcasing the distinctive double crests and other skeletal features. Detailed fossils have revealed intricate details of the skull and teeth, and postcranial anatomy, offering insights into its feeding habits and predatory behavior. These well-preserved specimens have been crucial in reconstructing the life and environment of this fascinating Early Jurassic predator.

Dilophosaurus Size and Description

Although ranking amongst the largest carnivores of its age, Dilophosaurus was a medium-sized theropod, notable for its sleek, agile build and distinctive double crests. These crests, which adorned the top of its head, were formed by upward extensions of the fused nasal and lacrimal bones, and may have been covered in a keratin coating – possibly resulting in even larger crests than that implied by the preserved bone tissue. The purpose of these crests remains a topic of debate, with theories ranging from display features used in mating rituals to possible roles in species recognition or thermoregulation.

Short Description of Dilophosaurus

Physically, Dilophosaurus had a long, slender body with a relatively light build compared to some later theropods. Its skull was large and equipped with a set of sharp, serrated teeth ideal for slicing through flesh. The neck was elongated and flexible, allowing for a wide range of motion, which would have been advantageous in capturing prey. Its cervical (neck) vertebrae were excavated by deep ‘pleurocoels’ – or air sacs – reducing weight without sacrificing strength. The limbs were robust, with strong, muscular legs adapted for swift movement, and it walked on two legs. The arms, though shorter, were likely quite strong and ended in hands with sharp claws. Its tail was long and used for balance, especially when running.

Size and Weight of Type Species

Estimates for the size and weight of Dilophosaurus wetherilli vary, but it is generally believed to have reached lengths of 20.0 to 23.0 feet. Standing about 6.0 feet tall at the hips, this dinosaur was a formidable presence in its environment. Weight estimates range from 660.0 to 990.0 pounds, making it one of the larger predators of its time. These measurements, however, are based on the available fossil evidence and can vary depending on the specimen, of which some appear to be represented by juveniles.

The variation in size estimates can be attributed to differences in the completeness of fossil specimens and the methods used to reconstruct the dinosaur’s body. Some specimens suggest a more gracile build, while others indicate a more robust frame. On average, Dilophosaurus likely weighed around 800.0 pounds, combining the agility needed for hunting with the strength required to overpower its prey.

The Dinosaur in Detail

Dilophosaurus stands out among early theropods due to its unique features and adaptations. The double crests on its head were likely a significant aspect of its appearance and possibly its behavior. These crests might have been used for display during mating rituals or as a means of intimidating rivals. Their exact function remains speculative, but they undoubtedly contributed to the dinosaur’s distinctive look.

Another notable feature of Dilophosaurus is its teeth. This dinosaur had a mix of long, curved teeth at the front of its mouth and shorter teeth further back, while the teeth in the lower jaw (mandible) were appreciably shorter than the teeth in the upper. All teeth were ovoid in cross-section and finely serrated. This dentition suggests a versatile diet that included both flesh and possibly carrion. The front teeth were likely used to grasp and hold onto struggling prey, while the back teeth could efficiently slice through meat.

The overall build of Dilophosaurus indicates an animal well-adapted to a predatory lifestyle. Its long legs and relatively lightweight body suggest it was an agile runner, capable of chasing down prey. The structure of its feet, with three primary toes, further supports this idea, providing stability and traction while moving at high speeds. Its long tail would have served as a counterbalance, helping to maintain stability during rapid movements.

Contemporary Dinosaurs

Sharing the landscape with Dilophosaurus was the small, early sauropodomorph Mussaurus. Unlike the carnivorous Dilophosaurus, Mussaurus fed on plants, indicating a diverse ecosystem where various niches were occupied by different species. With its long neck and herbivorous diet, Mussaurus likely inhabited areas abundant in vegetation, providing a stark contrast to the hunting grounds of Dilophosaurus.

Anchisaurus, another herbivorous dinosaur present during this period, was a sauropodomorph that was relatively small and bipedal. Similar to Mussaurus but with slight variations in its physical build and feeding habits, Anchisaurus would have coexisted with Dilophosaurus, perhaps frequenting different areas within the same ecosystem. The presence of these herbivores suggests a rich, verdant environment capable of supporting a variety of plant-eating dinosaurs, which in turn provided ample prey for the carnivorous Dilophosaurus.

Another contemporary of Dilophosaurus was Scutellosaurus, a small, armored ornithischian dinosaur. Unlike larger herbivores, Scutellosaurus had a unique defense mechanism in the form of bony plates covering its back and tail. This armor would have been a significant deterrent to predators like Dilophosaurus, showcasing the diversity of survival strategies among the dinosaurs of the Early Jurassic. Scutellosaurus likely moved in herds, using its armor to protect itself from threats while foraging for low-lying vegetation.

The coexistence of Dilophosaurus with these herbivorous contemporaries highlights the dynamic and interconnected nature of their ecosystem, with sufficient plant life to support multiple species, thus maintaining a stable food source for predators. This balance between predator and prey is a testament to the complex ecological interactions that defined the Early Jurassic landscape.

Interesting Points about Dilophosaurus

Dilophosaurus in its Natural Habitat

Dilophosaurus thrived during the Early Jurassic Period. A time marked by significant geological and climatic shifts that shaped a diverse range of dinosaur species. The Kayenta Formation, where Dilophosaurus fossils have been found, dates to the Sinemurian to Pliensbachian stages, approximately 196 to 186 million years ago. This formation, part of the Glen Canyon Group, spans northern Arizona, southeastern Utah, western Colorado, and northwestern New Mexico. It consists primarily of siltstone and sandstone facies. Deposited by rivers, with a seasonally dry environment characterized by migrating sand dunes and conifer-lined waterways. This varied terrain provided a rich array of habitats. Ranging from river valleys and floodplains to forested areas, supporting a diverse ecosystem.

Feeding and prey

As a carnivore, Dilophosaurus likely preyed on smaller dinosaurs and possibly scavenged carrion. Just like many modern predators are disinclined to pass up such an easy meal. Its strong legs and agile build suggest it was capable of chasing down swift prey. While its sharp, serrated teeth were perfect for tearing through flesh.

The presence of herbivorous dinosaurs like Mussaurus and Anchisaurus in the same regions indicates an abundance of prey available. Allowing Dilophosaurus to thrive as a top predator. Fossils from the Kayenta Formation reveal a vibrant ecosystem,. Including various vertebrates like lungfish, salamanders, early crocodylomorphs, and other dinosaurs, all contributing to the dynamic food web.

Dilophosaurus was probably a solitary hunter, relying on its speed and agility to capture prey. Its long tail provided balance during rapid movements. Its keen senses, including sharp eyesight and a heightened sense of smell, made it an effective predator. The distinctive crests on its head, while their exact function remains unknown, might have played a role in communication or mating displays, adding a social dimension to its behavior. The well-preserved fossils of Dilophosaurus, often found in the “death pose” with recurved necks, indicate they were buried close to where they died, sometimes disturbed by scavengers. This taphonomic evidence provides insights into the post-mortem processes and the environment in which these fascinating creatures lived.

Frequently Asked Questions

Sources

The information in this article is based on various sources, drawing on scientific research, fossil evidence, and expert analysis. The aim is to provide a comprehensive and accurate overview of Dilophosaurus. However, please be aware that our understanding of dinosaurs and their world is constantly evolving as new discoveries are made.

Article last fact checked: Joey Arboleda, 07-19-2024

Featured Image Credit: Leandra Walters, published by Phil Senter and James H. Robins, CC BY 2.5, via Wikimedia Commons