An Ultimate Guide to Proceratosaurus: The Slender-Horned

Leave a comment / / Updated on: 22nd October 2023

Name Meaning“Before the horned lizard”Height1 meter (3.3 feet)
PronunciationPro-seh-rat-oh-sore-usLength3–4 meters (9.8–13.1 feet)
EraMesozoicMiddle JurassicWeight28–100 kilograms (62–220 pounds)
ClassificationDinosauria, Saurischia, & TheropodaLocationEngland

Proceratosaurus Pictures


The Proceratosaurus

Gage Beasley Prehistoric's Proceratosaurus Concept
Gage Beasley Prehistoric’s Proceratosaurus Concept

Although previously considered an ancestor of Ceratosaurus (hence its name), Proceratosaurus is now widely accepted as part of the Tyrannosauroidea superfamily. 

It is regarded as the earliest member of this group and part of the lineage that led to the appearance of the ferocious T-Rex.

The name of the genus and its species, Proceratosaurus and P. bradleyi, respectively, were coined by Friedrich von Huene in 1923, two decades after the discovery of the partial skull, the only fossils associated with the genus.

Considering the lack of remains, Proceratosaurus is relatively poorly known compared to other dinosaurs. 

However, scientists did their best to use the available material and outline details that will help dinosaur enthusiasts understand this creature’s characteristics and behavior.

If you want to learn more about an early tyrannosauroid that walked the territory of prehistoric England 166 million years ago, continue reading as we’ve gathered some awe-inspiring facts!

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Physical Characteristics

Illustration of a Proceratosaurus dinosaur standing upright | SEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY via GettyImages

Proceratosaurus is only known from a partial skull. Therefore, outlining a precise appearance is quite challenging. 

However, we will turn to what is known about other members of the Proceratosauridae groups, trying to guess some particular characteristics.

Proceratosaurus had a low, elongated skull, like other basal tyrannosauroids.

Later forms, on the other hand, evolved with taller, more massive skulls. Nevertheless, both earlier and later forms had very tall premaxillary bones.

The premaxillary teeth of Proceratosaurus were small, while the lateral teeth were larger. 

Its enlarged external nares and the cranial crest protruding from the premaxillary make Proceratosaurus stand out among other theropods.

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

The skull length of Proceratosaurus was estimated at 30 centimeters (11.9 inches), while the proposed body length was 2.98–3.16 meters (9.8–10.4 feet), although other sources argued it could have reached almost 4 meters (13.1 feet). 

The weight hasn’t been fully confirmed but probably ranged from 28 to 100 kilograms (62–220 pounds).

Alongside Guanlong, Proceratosaurus is the smallest member of the Proceratosauridae family. 

Other members, like Yutyrannus and Sinotyrannus, reached 9–10 meters (29.5–33 feet) in length.

Proceratosaurus was a bipedal dinosaur. Its three-fingered forelimbs were short but probably did well in grasping prey.

Habitat and Distribution

The skull of Proceratosaurus was discovered in the Cotswolds, Gloucestershire, England.

During the Middle Jurassic, when Proceratosaurus roamed Earth, our planet went through a cooling interval that started 174 million years ago and ended 164 million years ago.

Besides this, Earth experienced a major change during the Jurassic – the supercontinent of Pangaea started breaking up into Laurasia and Gondwana. 

The territory we now call England was located on the supercontinent of Laurasia.

Laurasua and Pangaea
Laurasua and Pangaea | Image via lsintspl3.wgbh

During this process, Europe turned into an archipelago of islands, and most of the territories were surrounded by shallow seas.

Therefore, Proceratosaurus and other dinosaurs thrived in a coastal environment filled with multiple water sources. 

The territory may have experienced seasonal dry periods.

During the Middle Jurassic, England was probably dominated by ferns, cycads, ginkgos, and conifers.

Behavior and Diet

The carnivorous Proceratosaurus dinosaur | SEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY via GettyImages

Like other theropods, Proceratosaurus was a carnivore. Skull characteristics and tooth marks show it likely relied on a puncture-pull biting strategy. 

Additionally, its arms may have been well-developed and powerful enough to capture and hold onto prey while delivering bites.

The same feeding strategy is suspected in the youngest and probably most famous tyrannosaurid, Tyrannosaurus rex

This indicates that certain characteristics observed in tyrannosaurids may date back to the Middle Jurassic.

On the other hand, while the T-Rex had a very strong bite force, Proceratosaurus didn’t excel at this part. 

Scientists believe its teeth and jaws weren’t powerful enough to crush bones, so it may have relied on small prey, possibly even salamanders, lizards, or mammaliamorphs.

Theropods are renowned for hunting and killing sauropods and other herbivorous dinosaurs, but Proceratosaurus was likely too small to aim for large prey. 

The herbivorous Cetiosaurus dinosaur | CoreyFord via iStock

For example, England was home to Cetiosaurus during the Bathonian. 

This sauropod measured 16 meters (52.5 feet) long and weighed 11 metric tons (12 short tons).

There’s no way a Proceratosaurus could have killed this giant unless it hunted in large packs and had complex hunting and social skills!

One may expect that the distinctive crest of Proceratosaurus was a hunting aid. 

Could this theropod have used its crest to crush prey? It’s highly unlikely. 

Studies show that the crest was rather delicate and fragile, and it may have been a disadvantage in the process of catching and subduing prey.

Life Cycle

Proceratosaurus dinosaur looking for food on the ground | SEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY via GettyImages

Proceratosaurus individuals may have relied on their remarkable crest to engage in courtship behavior. 

The crest probably played an important role in sexual selection. 

Apparently, this advantage outweighed the risk of losing in a hunting-related confrontation. After all, successful mating ensured the continuation of the species!

As much as we’d like to share extensive details about the reproductive system and life cycle of Proceratosaurus, there’s little information we could use. 

This genus is known from a single, incomplete skull, so not even its postcranial skeleton is clearly outlined. Even less is known about its growth stages.

The egg-laying Proceratosaurus | Nobumichi Tamura/Stocktrek Images via GettyImages

What we can state for sure is that Proceratosaurus, like other dinosaurs, reproduced by laying eggs. 

Males likely had a retractable penis and internal testes, while females had two ovaries and oviducts, which means they laid two eggs at a time. 

By contrast, most modern birds lay only one egg at a time.

It remains unknown whether Proceratosaurus incubated its eggs, but we cannot rule out this possibility, considering that at least some theropods are known to have engaged in incubation.

Studies on theropod growth rates showed that all non-avian theropods grew faster than extant reptiles. 

As they grew larger, the growth rate increased. Scientists believe this is an adaptation prompted by the necessity of reaching the required size to become sexually mature faster.

Procerotasurus dinosaur walking in white background | Cyrannian via JWE Fandom

If we were to judge by how scientists classify theropods in terms of size and growth rates, we’d compare Proceratosaurus with Microraptor, which weighed 200 grams (7.1 ounces). 

Microraptor hatchlings added 0.33 grams (0.01 ounces) a day. Naturally, these numbers would slightly differ for Proceratosaurus, as it weighed much more.

Nevertheless, the genus is closer to Microraptor than those in the medium-sized group of non-avian theropods, which probably weighed between 100 and 1,000 kilograms (220–2,200 pounds) and exhibited different growth rates. 

This aspect is important in outlining the ontogeny of dinosaurs, as growth rates depend much on their weight.

In short, we could speculate as much as we’d like, but until further research is conducted, nobody knows precisely how fast Proceratosaurus grew and how long its lifespan was.

Evolution and History

Camposaurus | Warpaintcobra via iStock

The most primitive unambiguous theropods date from the Late Triassic, Camposaurus and Coelophysis being some of them. 

They were part of the Coelophysoidea group and thrived until the early Jurassic. 

Then, more advanced ceratosaurs evolved, which competed with more specialized tetanurans, a group that includes Proceratosaurus.

Further down the taxonomic tree, Tetanurae is split between Megalosauroidea and Avetheropoda

Proceratosaurus is part of the latter and is, therefore, more closely related to birds than megalosauroids.

Tyrannosauroids are then placed under the avetheropod subgroup Coelurosauria, which turned out to be the most diverse theropod group.

Holotype skull of Proceratosaurus
Holotype skull of Proceratosaurus | Trustees of the Natural History Museum, London via iStock CC BY 4.0

The Proceratosaurus skull was discovered in 1910 in the Cotswolds, Gloucestershire, England, by Arthur Smith Woodward. 

At first, the paleontologist classified the remains as belonging to Megalosaurus.

Two decades later, a study published by Friedrich von Huene, a German paleontologist, showed that the fossils were more closely related to Ceratosaurus, so they must belong to the Coelurosauria genus.

Therefore, he moved the fossils to a newly coined genus – Proceratosaurus. In fact, Friedriech von Huene argued that Proceratosaurus was an ancestor of Ceratosaurus, considering how similar their crests were.

Proceratosaurus ready to pounce targets | Gigantisuniversecreator via Jurassic Park Fandom

This theory remained in place until the 1980s, when it was suggested that the genus was a much more primitive theropod.

Other theories implied that Proceratosaurus was a primitive allosauroid and that Proceratosaurus was synonymous with Piveteausaurus.

Only in 2010 did scientists confirm that Proceratosaurus was indeed a coelurosaur, a tyrannosauroid, and an ancestor of the large Late Cretaceous tyrannosaurs.

Upon studying its morphology and evolution, they concluded that Guanlong was the closest relative of Proceratosaurus and, therefore, coined a group for the two – Proceratosauridae – which was later joined by other genera.

Interactions with Other Species

A Proceratosaurus dinosaur looking forward | SEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY via GettyImages

England’s territory in the Middle Jurassic was undoubtedly an environment where prehistoric animals thrived, as the geological formations revealed multiple fossils that are now of major significance in paleontology.

As such, Proceratosaurus likely shared its habitat with the following creatures:

  • Sauropods like Cardiodon and Cetiosaurus
  • Dromaeosaurids
  • Theropods like Megalosaurus, Iliosuchus, and possibly Cruxicheiros
  • Amphibians like Anoualerpeton and Marmorerpeton (salamanders)
  • Aquatic reptiles like Cteniogenys
  • Squamates like Parviraptor
  • Mammaliamorphs like Amphitherium, Borealestes, Dubunnodon, and Phascolotherium
  • Pterosaurs like Klobiodon
  • Crocodyliforms like Teleosaurus
  • Various fish species
  • Beetles
  • Dragonflies
Life restoration of Proceratosaurus
Life restoration of Proceratosaurus | Nobu Tamura via Wikipedia CC BY-SA 3.0

As already mentioned, we do not know what Proceratosaurus preferred as prey. Considering its small size, we’d suspect it went for creatures like lizards or mammaliamorphs.

Proceratosaurus also shared its habitat with a larger carnivorous theropod called Megalosaurus, which probably had the upper hand in catching large prey.

Other carnivores, however, like the ferocious Teleosaurus, did not cross paths with Proceratosaurus, as it lived in the open ocean and preyed on fish and squid.

Cultural Significance

Proceratosaurus is now widely regarded as the earliest member of the Tyrannosauroidea group of theropods. 

Its discovery led to multiple revelations regarding the evolution and radiation of tyrannosauroids.

3D Image of Proceratosaurus | 671593ro via Godzilla and Friend Fandom

Moreover, the fossilized Proceratosaurus skull carried important information related to the evolutionary history of coelurosaurs, a major theropod clade.

If you want to check out the fossils that belonged to the earliest member of the lineage that led to the rise of the renowned T-Rex, add London’s Natural History Museum to your must-visit list, as the skull is currently on display there!

Additionally, Proceratosaurus can be seen in the Jurassic World: Evolution video game as well as in Dino Dana, an Amazon Prime series.


Proceratosaurus was an inhabitant of Middle Jurassic England. 

It roamed through Earth 166 million years ago and shared its habitat with a myriad of other unique creatures, including other dinosaurs, pterosaurs, various reptiles, and even crocodyliforms.

The genus is described only from a partial skull, so many aspects of its appearance and lifestyle remain a mystery until future findings.

Scientists suggested that Proceratosaurus was a bipedal carnivore with short forelimbs that may have helped it hold onto prey. 

Its skull was elongated and low, compared to the skulls of later tyrannosauroid forms, which were rather tall. 

It also had a distinctive crest that may have played a role in sexual selection.

Paleontologists estimate that Proceratosaurus was quite small, measuring only 3–4 meters (9.8–13.1 feet) long and weighing up to 100 kilograms (220 pounds). 

Despite this, it was probably an efficient predator that relied on a puncture-pull feeding strategy.


Is Proceratosaurus a Tyrannosaurus?

Proceratosaurus is a tyrannosauroid, but not a Tyrannosaurus. Tyrannosaurus (T-Rex) is a separate genus consisting of Late Cretaceous theropods. Proceratosaurus and the T-Rex lived in different periods, having been separated by 100 million years. They are part of the same lineage.

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