An Ultimate Guide to Monolophosaurus: Single-Crest Lizard

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Name Meaning“Single-crested lizard”Height2.5 meters (8.2 feet)
PronunciationMon-o-lo-fo-SAW-rusLength5 to 6 meters (16 to 20 feet)
EraMesozoicMiddle JurassicWeight500 to 1,000 kilograms (1,100 to 2,200 pounds)
ClassificationDinosauria,‭ Saurischia & TheropodaLocationChina

Monolophosaurus Pictures

Monolophosaurus 3D rendering -
Monolophosaurus 3D rendering | Vac1 via iStock

The Monolophosaurus

Gage Beasley Prehistoric's Monolophosaurus Concept
Gage Beasley Prehistoric’s Monolophosaurus Concept

The carnivorous theropod dinosaur known as Monolophosaurus (from Greek for “single-crested lizard”) lived around 170 million years ago, during the Middle Jurassic period.

The dinosaur is linked to such well-known genera as Dilophosaurus and the rest of the Dilophosaurus.

In 1981, its skull, jaws, vertebrae, and limb bones were discovered in the Xinjiang region of China.

Researchers have been able to put together more information about the creature’s anatomy and behavior thanks to these fossils.

Monolophosaurus deserves acknowledgment because it was a fascinating intermediate stage in the evolution of theropod dinosaurs.

Monolophosaurus 3D Face
Monolophosaurus 3D Face Render | CoreyFord via iStock

It has characteristics in common with both early theropods and more advanced, later theropods.

This dinosaur’s fossils are crucial to unraveling the history of its family tree.

The historical significance of the Monolophosaurus and the present state of knowledge about the beast will be discussed here.

By the time we finish this article, you should know more about Monolophosaurus, including its anatomy, habits, and place in dinosaur history.

Gage Beasley's Prehistoric Shirt Collection
Gage Beasley’s Prehistoric Shirt Collection
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Gage Beasley’s Prehistoric Plush Collection

Physical Characteristics

Gage Beasley Prehistoric's Monolophosaurus Size Comparison Chart
Gage Beasley Prehistoric’s Monolophosaurus Size Comparison Chart

Monolophosaurus was an unusual dinosaur due to its unique anatomy. 

An adult Monolophosaurus measured between 5 and 6 meters (16 to 20 feet) in length, with a height of around 2 meters (6.5 feet) at the hips.

It had a solid structure and a muscular build, making it seem well-built.

It was bipedal, evident from its hind limbs being far longer than its front ones.

Because of its predatory lifestyle, its anatomy was tailored to maximize its speed and agility.

Monolophosaurus was easily recognized by the distinctive, singular crest that adorned its skull.

Monolophosaurus skull
Monolophosaurus skull | Kabacchi via License

The peak narrowed into a sweeping arc as it moved backward.

Despite several theories, scientists still can’t agree on the crest’s function.

Possible functions include species identification and visual communication between individuals.

Thermoregulation, in which blood flow impacts core body temperature, or acts as a heat sink may have also been a function of the crest.

To learn more about Monolophosaurus, it’s helpful to look at how it compares to other dinosaurs, especially Dilophosaurus.

Dilophosaurus, like Monolophosaurus, had crests, but these were two smaller crests on each side of its head.

This variation serves as another evidence of the diverse skull adaptations seen among Dilophosaurus members.

The crest on Monolophosaurus’ head wasn’t the only distinctive feature of its body.

Its long, narrow nose was lined with sharp, serrated fangs that were perfect for grabbing and ripping apart whatever it happened to be hunting.

Sketch of Monolophosaurus jiangi
Sketch of Monolophosaurus jiangi | Jordan Mallon via License

The jaws were strong, allowing Monolophosaurus to bite fast and with great force.

Its eyes were set far apart on the side of its head which gave it a broad field of vision for scanning the area for both prey and danger.

Monolophosaurus’ soft tissues were ineffectively preserved in the fossil record, therefore our understanding of its scale pattern and texture is limited.

These scales might have protected the animal from harm and helped it maintain the same internal temperature.

The long, stiff tail that Monolophosaurus had likely helped it maintain its stability when chasing prey or making territorial threats.

Habitat and Distribution

Dimorphodon Pterosaur fly over a Monolophosaurus theropod carnivorous dinosaur in a wetland area.
Pterosaurs fly over a Monolophosaurus | CoreyFord via iStock

The Middle Jurassic range of Monolophosaurus was strongly influenced by geographical variables and the kinds of habitats that were accessible in those areas.

According to fossil records, Monolophosaurus probably roamed what is now China.

The Middle Jurassic skeletons have been discovered in Xinjiang, a location that was once a component of the supercontinent Pangaea.

While the Monolophosaurus could prosper in a wide variety of ecosystems, it was most at home in settings that combined wooded and grassy terrain.

Monolophosaurus would have found an abundance of the smaller dinosaurs and other animals, its primary food source, in these areas.

Climate and ecosystems were very different during the Middle Jurassic era compared to the present day.

Temperatures on Earth were higher than they would be in succeeding epochs, and a tropical, humid climate would rule.

Ferns, cycads, and conifers grew abundantly over the landscape.

Monolophosaurus roaring next to a cycadeoidea plant
Monolophosaurus roaring next to a cycadeoidea plant | Elenarts108 via iStock

Monolophosaurus was only one of many dinosaurs that shared this flourishing ecology.

Herbivorous dinosaurs like the legendary Stegosaurus and Apatosaurus, and theropods like Yangchuanosaurus and Guanlong, were among their contemporaries.

This ever-changing setting encouraged the development of elaborate food chains and relationships between predators and prey.

Knowing where Monolophosaurus lived and when may provide light on its ecological niche and its role in the ancient environment.

Scientists may piece together the settings these dinosaurs called home by analyzing geological and fossil data, providing a window into the ancient world of these creatures.

Behavior and Diet

One monolophosaurus dinosaur walking near cycas and calamites by day - 3D render
On the morning prowl | Elenarts108 via iStock

The lack of fossils makes it difficult to draw firm conclusions on Monolophosaurus’ behavior, but research into other theropods may provide light on the dinosaur’s possible traits and adaptations.

The hunting methods used by Monolophosaurus were very efficient.

Their powerful jaws and deadly fangs gave it the ability to grab and rip into flesh.

Speed and mobility allowed it to either surprise its victim or aggressively pursue it.

Its physical traits and hunting reflexes together could have made it a powerful predator, albeit the specific hunting strategies are speculative.

The predatory Monolophosaurus preyed upon several different species.

Prey items are not extensively recorded, but it is safe to assume that herbivorous ornithopods and other theropods, notably sick, old, or young ones, were among them.

Monolophosaurus’ adaptability to varying ecological settings would have been aided by its wide array of prey options.

After the hunt had been accomplished, the Monolophosaurus would have ripped the corpse apart with its powerful jaws and keen teeth.

Monolophosaurus jiangi Zhao & Currie, 1993 theropod dinosaur (reconstruction)
Sharp teeth built for quick dispatches | James St. John via License

It would have digested most of the animal to get the most out of the food it caught.

The fossil record reveals that Monolophosaurus ate a wide variety of foods, demonstrating a high degree of dietary flexibility.

It’s possible that Monolophosaurus, like many predators, sometimes scavenged for food.

Carnivores may benefit greatly from scavenging.

While Monolophosaurus probably did some scavenging in its day, such activity was probably secondary to its principal function as a predator. 

There is no evidence that Monolophosaurus engaged in intricate social relationships or exhibited social behaviors, hence the dinosaur is assumed to have been solitary.

Likely, it hunted on its own and relied only on its skills to bring down prey.

The possibility of chance interactions between individuals for breeding or territorial conflicts, however, cannot be discounted.

Life Cycle

Illustration of an adult and a young Monolophosaurus
Illustration of an adult and a young Monolophosaurus | XiaImages via iStock

When compared to other extinct reptiles, the Monolophosaurus’s life cycle becomes clearer.

For instance, by contrasting the reproductive strategies, body sizes, and longevity of closely related theropod dinosaurs, we may get insight into overarching patterns in the evolution and life cycle strategies of these extinct species.

Even though the specifics of Monolophosaurus‘ life cycle remain speculative, studying its mating habits, developmental phases, and lifespan helps us understand its biology and places it within the larger framework of ancient life.

Monolophosaurus likely reproduced sexually, with adults pairing together to have children.

It would have laid eggs, and its offspring would have matured rapidly.

Although we don’t know much about their behaviors, similarities to other dinosaurs may provide some information regarding what to assume.

Courting displays and actions were likely part of Monolophosaurus’ mating ritual.

3D rendering of a dinosaur Monolophosaurus isolated on white background
Here I am! | Vac1 via iStock

They may have used intricate body motions, vocalizations, and actions as signals of their physical well-being and readiness.

Male Monolophosaurus also likely engaged in aggressive competition for the consideration of females, using displays of superiority and battles to prove their fitness for reproduction. 

Once a partnership was established, mating most likely happened by sexual contact.

Like other theropod dinosaurs, Monolophosaurus likely reproduced sexually, as shown by the discovery of fossilized nesting sites and eggs.

Eggs would have been laid in nests and cared for by the female until they hatched.

Lifespan estimates for Monolophosaurus are uncertain, although similar theropods range several to tens of years.

Size, growth rate, and environmental factors all had a role in how long it lived.

Evolution and History

Monolophosaurus holotype at Paleozoological Museum of China
Monolophosaurus holotype at Paleozoological Museum of China | BleachedRice via License

Although a largely complete skeleton of Monolophosaurus was discovered during the Canadian-Chinese expeditions (1981–1984), it wasn’t named until Dong Zhiming in 1992 and Wayne Grady in 1993.

However, these earlier namings lacked descriptive detail, and the species wasn’t fully recognized and described until 1993–1994.

It is currently known as Monolophosaurus jiangi.

The theropod dinosaurs include well-known names like Tyrannosaurus rex and Velociraptor, and Monolophosaurus is one of them.

Monolophosaurus is regarded as a transitional or early member of the theropod lineage, standing between more primitive theropods and more complex theropods that evolved later.

Scientists have uncovered significant elements in Monolophosaurus that connect it to both early basal theropods and later, more evolved, theropod families by studying similar anatomical features.

The general layout of its body, the shape of its cranium, and the arrangement of its bones are all examples.

A Monolophosaurus skull
A Monolophosaurus skull | Ghedoghedo via License

As theropods developed, new lineages took on new functions in the ecosystem and acquired unique physical and behavioral traits.

Monolophosaurus is illustrative of a transitional phase in the development of theropods because of the mix of primitive and evolved characteristics it displays.

While not the sole transitional species, Monolophosaurus sheds light on the evolutionary gap between primitive and contemporary theropods.

In-depth anatomical and phylogenetic studies of Monolophosaurus have been done to discover its evolutionary relationships and linkages to other theropods, which has helped scientists get a better understanding of dinosaur evolution as a whole.

Interactions with Other Species

The theropod dinosaur Monolophosaurus likely had a diverse set of neighbors.

Being a predator, it most likely preyed upon other, smaller dinosaurs and animals.

Gage Beasley's Yangchuanosaurus Concept
Yangchuanosaurus likely encountered our profiled dinosaur

It’s possible that it had to contend with other carnivorous dinosaurs for food and territory.

Fossil evidence for particular symbiotic connections between Monolophosaurus and other creatures is sparse, however, this dinosaur probably had commensal or mutualistic relationships with smaller animals.

Cultural Significance

Monolophosaurus theropod dinosaurs search for prey along an ocean beach as Dorygnathus reptiles fly over.
2 Monolophosaurus scouting the beach | CoryFord via iStock

The media and academic study of Monolophosaurus have cultural and historical relevance.

Because of its distinct characteristics and intimidating physical appearance, it has been featured prominently in many kinds of popular culture.

Monolophosaurus has made cameos in various major film and television series.

It made an appearance in the B-movie “Jurassic City,” demonstrating the film industry’s appreciation for its mesmerizing attractiveness. 

The dinosaur has an important place in television culture as well.

The inclusion of Monolophosaurus in “Jurassic World: Camp Cretaceous” furthers the dinosaur’s cultural clout by bringing it to the attention of a wider audience.

The dinosaur also appears in several video games, including “The Isle,” “Jurassic Park III: Park Builder,” and “Jurassic World: The Game.”

Monolophosaurus in-game concept
An in-game concept | Added by DinoBoi6491 in JurassicPark Fandom

The inclusion of Monolophosaurus in these interactive platforms enables users to explore the intriguing world of this dinosaur and its ancestors.

Toys and other products featuring Monolophosaurus have also become popular.

The “Jurassic World: Fallen Kingdom” toy line included the first ever Monolophosaurus action figure, which made its debut in a Jurassic Park-themed toy set. 

The study of Monolophosaurus has aided in our understanding of the biology and evolution of dinosaurs.

Paleontologists have researched its remains and distinctive traits to learn more about the evolutionary history and anatomy of theropod dinosaurs.

Additionally, Monolophosaurus has made an appearance in academic circles.

A fascinating fight between a Monolophosaurus and a Tuojiangosaurus is on display as skeletons at Chicago’s Field Museum.

This exhibit gives viewers an insight into the complex social lives and prehistoric environments of these fascinating animals.


Future research into Monolophosaurus promises new understanding of this interesting dinosaur and its position in evolutionary history.

More study of its bones, anatomical details, and genetic analysis will provide light on its physical traits, behavioral patterns, and kinship with other dinosaurs.

Technological and analytical advancements have the potential to reveal previously unknown information and provide answers to issues about Monolophosaurus’ life cycle, social behavior, and ecological relationships.

Future research into this fascinating dinosaur has the potential to increase our understanding of the ancient world and improve our ability to recreate its environment.


When and why did the Monolophosaurus go extinct?

Monolophosaurus, like all non-avian dinosaurs, went extinct around 65 million years ago.

The most widely accepted theory is that their extinction was caused by a catastrophic event, such as an asteroid impact, leading to widespread environmental changes and the collapse of ecosystems worldwide.

What natural predators did Monolophosaurus face?

Since Monolophosaurus was already a top predator in its ecology, it was probably safe from any other animals.

It’s possible, however, that other enormous carnivorous dinosaurs of the period provided some competition.

Could Monolophosaurus be regarded as the bird’s direct ancestor?

The theropod dinosaur Monolophosaurus is a member of the group that also contains modern birds. While it does have some similarities to birds, it is not thought of as a direct ancestor.

Instead, it is a distinct lineage within the theropod family tree.


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