Metriacanthosaurus parkeri (S/F) / (S/F-JWE)

Metriacanthosaurus is a medium-sized theropod dinosaur in the family Metriacanthosauridae. It lived in the Oxfordian epoch of the upper Jurassic period approximately 160 million years ago in what is now England, with fossils being found in the Oxford Clay Formation. Its genus name means “moderately-spined reptile,” referring to its distinctively medium-height vertebrae. The specific epithet honors W. Parker, who collected the fossil remains of this species in the nineteenth century.

It was described in 1923 in Dorset, England by German paleontologist Friedrich von Huene, who originally classified it as a species of Megalosaurus. He reviewed the few known remains, which consisted of part of a hip, a leg bone, and some vertebrae, as material for a paper about carnivorous dinosaurs from Europe. The fossils had been collected from near Jordan’s Cliff, in the upper Oxford Clay Formation near Weymouth. In 1932, von Huene determined that the fossils instead belonged to a species of Altispinax.

In 1964, Alick Walker revised the fossils and found that the fossil backbone was not tall enough to belong to Altispinax. He assigned it to a new genus, Metriacanthosaurus, because the bones of its spine were shorter than those of theropods like Acrocanthosaurus but taller than those of most carnosaurs such as Allosaurus.

In 1988, Gregory S. Paul considered the closely-related genus Yangchuanosaurus to be a species of Metriacanthosaurus; however, this was contested in 2007 by Darren Naish and David Martill, who determined that the two genera should be separate.

Metriacanthosaurus embryo in cold storage, Isla Nublar (6/11/1993)

Its genetic material was collected by International Genetic Technologies during the late 1980s and early 1990s, and as of 1993 its genome was reported at 71% completion. InGen had, at that time, created up to Version 1.02 of the animal, but did not have any living specimens on hand by the time of the 1993 incident. Over a decade later, it would be cloned by InGen under the banner of Masrani Global Corporation, but would become extinct by early 2018.


Fossils of Metriacanthosaurus are rare and fragmentary, so estimates of its size and appearance are based on its close relatives. Its femur measures 80 centimeters (31 inches) in length, and its size has been estimated at 10.5 meters (34.4 feet) long, 2 meters (7 feet) tall at the hips, and one metric ton (1.1 US short tons) in weight.

Specimens cloned by InGen attain lengths of 7.9 meters (26 feet), heights of 3.35 meters (11 feet), and weighed up to 0.91 metric tons (1 US short ton). This makes it slightly smaller and lighter than some paleontological estimates. It has a fairly typical medium-sized theropod build, with a bulky head containing sharp, serrated teeth. Like most theropods, these teeth are replaced throughout life as they fell out. Over the eyes it possesses small triangular crests, which likely serve display purposes and may be used for species recognition. The jaws are shorter and blunter than some other theropods, giving it a distinct profile.

Its arms are rather small, and the three fingers each bear an average-sized claw. The legs, meanwhile, are considerably more powerful, allowing it to reach reasonable speeds. Its feet bear four toes each, the innermost of which is a reduced dewclaw which does not touch the ground. The remaining three toes possess small but thick talons. It stands fairly upright compared to some of the bigger carnosaurs.

Profile illustration of an adult Metriacanthosaurus. Note the very fine, short feather-like filaments which can be seen upon close observation of the body’s outline.

Over its body, particularly on the head and arms, Metriacanthosaurus has a thin, fine coat of simple feather quills. While not true feathers, this integument is unusual among InGen’s animals, most of which have bare scaly or leathery skin due to null alleles created by accident during the reconstruction of their genomes. This suggests that InGen manipulated the Metriacanthosaurus genome less than most other animals, as it does not have the null allele related to feather development.

It is among the more colorful theropods, particularly on the face. Most of its body is a woody tan color, but it is striped in light orange and muddy brown; these likely help it camouflage in forested environments similarly to a modern-day tiger. Its head lacks the orange color, bearing brown stripes; the stripe at the top of the neck has a dull yellow interior where its body stripes would have orange, and the third, fourth, and fifth stripes on the skull have lime green interiors. The first such stripe has this color mostly on the lower jaw, and the second green stripe includes the supraorbital crests.


Only the adult stage has been observed in this species.

Sexual Dimorphism

No information is known about sexual dimorphism in Metriacanthosaurus.

Preferred Habitat

Metriacanthosaurus prefer to hunt in dense forested environments. However, the Jurassic World website states that it lives comfortably on plains. This suggests it can acclimate to different types of habitats. The fossil formation where it was found, the Oxford Clay, is interpreted by paleontologists as having been a lush coastal environment with rivers and estuaries throughout.

Muertes Archipelago

While InGen would have performed cloning experiments and genetic reconstruction of Metriacanthosaurus on Isla Sorna, there is no evidence that any specimens were cloned there. InGen documentation lists it as having a viability rate of 71%, but none were alive at the time that the island facilities were abandoned.

Isla Nublar
On the board in the upper left are x-rays of what are believed to be Apatosaurus and Metriacanthosaurus, neither of which are listed in 1993 InGen documentation as having been alive at the time.

By the summer of 1993, InGen had Version 1.02 Metriacanthosaurus embryos incubating in Isla Nublar‘s laboratory; the genome was 71% complete at the time. An x-ray of a Metriacanthosaurus skull present in Dr. Laura Sorkin‘s laboratory has been suggested as evidence that the animal had been cloned at some point, but official InGen documentation demonstrates otherwise; this x-ray was more likely taken from a fossil or replica skull.

A paddock for Metriacanthosaurus was being prepared as of 1993, despite the animal not yet having any viable specimens. The paddock, which was already advertised on the Jurassic Park brochure map found in the Ford Explorer tour vehicles, would have been in the northeastern region of the Park on the coastal side of the eastern mountain range. To the northeast it would have bordered the paddock area’s perimeter fence, and to the northwest and south it would have been separated from undeveloped areas by a twenty-four-foot fence. To the west, the main tour road and a set of five-foot-high electric fences would have separated it from the primary Triceratops paddock.

Planned (orange) paddock area for M. parkeri, as of June 11, 1993

Under the banner of Masrani Global Corporation, InGen completed the Metriacanthosaurus genome and cloned the animal for Jurassic World sometime before 2014. They inhabited the Jungle River area, most likely separated by means of artificial barriers from the other dinosaurs in their habitat. It is not known how many Metriacanthosaurus lived on Isla Nublar, but their highly aggressive behavior would suggest that their population was fairly low.

Although the date at which they were cloned is not known other than they existed by 2014, the manner in which they were portrayed on the Jurassic World website implies that they were a fairly new addition. The website features an illustration rather than a three-dimensional render of the animal, which inside sources have described as the artist’s rendition of what the animals would have looked like. This suggests that, at the time the website was developed, none of the Metriacanthosaurus had yet reached adulthood.

Following the island’s abandonment due to the 2015 incident, Metriacanthosaurus continued to live in the forested regions of Isla Nublar where it hunted smaller dinosaurs. As of February 4, 2018, it was stated by the Dinosaur Protection Group to have become extinct; according to a June 5 report, this species was the most recent carnivore to die out on Isla Nublar. Likely reasons for its decline and extinction include intense competition for resources with other carnivores, and the loss of common prey items due to volcanic activity and heavy predation.

Mantah Corp Island

This does not seem to have been one of the species Mantah Corporation illegally acquired from InGen. They operated a facility on the nearby Mantah Corp Island which exploited numerous de-extinct animals for profit, but no Metriacanthosaurus were reported among their menagerie as of 2016.

Biosyn Genetics Sanctuary

By the time de-extinct animals were released into the wild in the summer of 2018, Metriacanthosaurus had unfortunately already become re-extinct. Therefore, none were around to be apprehended by Biosyn Genetics in the early 2020s like their still-surviving neighbors. Acquisition of their DNA is still possible, but no cloning of this species appears to have taken place at the Biosyn Genetics Sanctuary before operations were put on hold. Currently, the valley is administered by the United Nations, and still serves as a de-extinct animal sanctuary; it may someday in the future house Metriacanthosaurus.

Black market

Poaching occurred in both the Muertes Archipelago and the area near Isla Nublar beginning in 1997 and continuing well into the early twenty-first century. It reached a peak around 2013, after which surveillance was increased around the islands. There is currently no evidence to confirm whether any Metriacanthosaurus were poached from Isla Nublar while Jurassic World was open, or that any were poached after the park closed and before the animal became extinct on the island.

This animal’s DNA is probably the only way it entered the black market following the events of 2018. Now, with de-extinction technology open source, anyone with enough money could recreate it if they so choose. Obtaining its DNA would be the first step: a good place to search for this is the Amber Clave night market, which operates clandestinely in Malta.

Wild populations

Metriacanthosaurus evolved during the Jurassic period, with its fossilized remains dating to about 160 million years ago. It lived on Laurasian islands which were precursors to the modern-day British Isles. While the rock formations where it may be found were coastal, it probably lived inland away from the sea as well, where its food would have been easier to find. Eventually, it became extinct as its environment changed; since its remains are so rare there is not much information about what ultimately caused it to die out. DNA samples were recovered by scientists many millions of years later, enabling them to clone this dinosaur during the early twenty-first century.

Neglect from its creators eventually caused it to fall back into at least regional extinction on Isla Nublar, and since no other populations were known, it may have become fully extinct. However, with modern technology, extinction has become reversible to a degree; in the future, Metriacanthosaurus may walk the earth once more.

Behavior and Ecology
Activity Patterns

An unused image for the Dinosaur Protection Group shows an adult Metriacanthosaurus active during the morning or daytime, but its normal activity patterns are unknown.

Diet and Feeding Behavior

As a medium-sized carnivore, Metriacanthosaurus preys on dinosaurs smaller than itself. It hunts in densely forested regions, suggesting that it attacks prey by ambush similarly to the much larger Tyrannosaurus. However, it also has strong legs which enable it to pursue prey if necessary; in Jurassic World: Evolution, it is capable of leaping onto medium-sized prey to tackle it to the ground before delivering a fatal bite. Like other theropods, its jaws are its main hunting implements.

Metriacanthosaurus, unknown date between late Dec. 2015 and very early Feb. 2018. Isla Nublar. Image from the Dinosaur Protection Group.

Small herbivores, such as Microceratus, likely made up much of its diet on Isla Nublar; it could theoretically have preyed on non-dinosaurian animals such as the common Nublar tufted deer, or scavenged scraps left behind by larger, more powerful carnivores. It appears to have been a less fit competitor in its environment, becoming extinct by early 2018.

Social Behavior

The social life of Metriacanthosaurus has never been studied in-depth, so details are scarce. They were known to be highly aggressive, but the bright colors of the supraorbital crests suggest that they were used for social interaction. Such social behavior is shown in the game Jurassic World: Evolution 2, in which they will engage in friendly shoving matches involving their heads. This places their crests within easy visual range, allowing them to inspect each other while they interact.


As with all dinosaurs, the Metriacanthosaurus would lay eggs to reproduce; presumably, the bright colors of the crests would play a role in mate selection, but anything else is entirely speculative. Its reproductive anatomy is unknown, but other theropods (including most birds) have cloacae.

Theropods lay ovoid eggs similar to those of modern-day birds, an evolutionary trait that ensures the eggs are less likely to roll away from where the parents place them. Medium-sized dinosaurs such as Metriacanthosaurus typically have incubation periods lasting up to six months, and many species practice extended parental care.


In Jurassic World: Evolution, vocalizations made by the Metriacanthosaurus include low-pitched growls and roars. In the sequel, its vocal repertoire is more inclined toward snarling and hissing when they interact with each other, since its social behaviors are expanded in this game; when idle, it may grunt and groan to itself, and it still roars and howls when confronting rivals.

Ecological Interactions

Little is known about the ecology of Metriacanthosaurus, though in life it would have lived in coastal regions. After being cloned by InGen, it was housed near a river within a forested area. In order for InGen to have cloned it in the first place, it would have been host to hematophagous animals such as female mosquitoes; it is not known if any modern parasites affect it in the same way.

It still preferred forested regions after being abandoned by Masrani Global Corporation. If they remained near the Jungle River, their neighbors would have included the fish-eating Baryonyx and Suchomimus, with which it may have competed for territory. Herbivores in this area included the sauropod Apatosaurus, the stegosaur Stegosaurus, the hadrosaur Parasaurolophus, and the tiny ceratopsian Microceratus, as well as around a hundred other species of de-extinct animals and plants as well as modern flora and fauna. It may have preyed upon the smaller of these species as well as the young of larger animals.

In general, Metriacanthosaurus is a mid-level predator; it was larger than Velociraptor or Deinonychus, but smaller than apex predators like Tyrannosaurus. It is close in size to Allosaurus and Carnotaurus, but is not as capable of taking down large prey. These traits likely made it a poor competitor in the wild on Isla Nublar, potentially leading to its extinction.

In Jurassic World: Evolution, it is particularly susceptible to infections of parasitic hookworms.

Cultural Significance

Because it is not very well-known to the public, Metriacanthosaurus is rarely ever depicted in art media. Its species name honors a fossil collector named W. Parker, who originally discovered its remains in England.

In 2018, it was used by the Dinosaur Protection Group (along with Edmontosaurus) to represent the consequences of failing to save de-extinct life from the Mount Sibo crisis. By this time, it had become extinct due to inaction.

In Captivity

Since the 1990s, InGen had plans to exhibit this obscure theropod in Jurassic Park, making it visible from the main tour road. It was not successfully cloned until years later, though; it was put on exhibit successfully in Jurassic World sometime prior to late 2014. Tourists could view it from the Cretaceous Cruise attraction while kayaking down the Jungle River.

Metriacanthosaurus is highly aggressive, though no interactions with humans have been directly reported. Its aggression and predatory behavior might make it view humans as potential prey, or as competition. This would make it more of a high-maintenance resident at Jurassic World, with the Asset Containment Unit requiring extra attention to regulate its behavior and prevent it from leaving its designated zone.


Aside from the paleontological and genetic knowledge gained from studying Metriacanthosaurus (both fossils and de-extinct specimens), this species has not been featured much in scientific research. Only a small amount of information appears available on its ecology, and as it became extinct by early 2018, nothing new can yet be learned.

Jurassic World: Evolution describes it as being enigmatic and poorly-known, suggesting that it was still scientifically neglected after being cloned.


After the closure of Jurassic World in late 2015, this dinosaur’s fate was hotly debated by Masrani Global Corporation and the governments of the United States and Costa Rica. Providing veterinary care to theropods was considered controversial because some of these species view humans as potential prey.

Unfortunately, Metriacanthosaurus had already died out by the time the debates surrounding Mount Sibo were publicized by the Dinosaur Protection Group. The extinction of Metriacanthosaurus was utilized by the DPG to represent the consequences of inaction regarding the ecological crisis on Isla Nublar. The government and Masrani Global failed to heed these warnings and permitted the rest of the island’s animal life to die out.


Although it is not a well-understood or popular dinosaur, it proved its value as an attraction at Jurassic World and was a unique addition to the Cretaceous Cruise. Here it stood out as distinctly different from the spinosaurs that otherwise made up the Jungle River’s roster of theropod attractions.

This species would have yielded biopharmaceutical compounds unique to its biology. Because it is believed to be extinct, no further research can go into it at this time.


Since Metriacanthosaurus is believed to be extinct, it is not likely you will encounter any, and there is currently little known about how it behaved when it was alive. However, we do know that it was one of the more aggressive theropods despite not being the biggest, and based on other theropods we can draw conclusions about what stimuli might trigger an aggressive response. Aside from situations where you are targeted as prey, the most common causes of theropod attacks are threats to its territory. These may involve you appearing as a danger to its safety, or the safety of its offspring. It might also attack if it believes you are a competitor for resources such as food and shelter. When you are out in areas where theropods may live, be on the lookout for signs that they are nesting or feeding in the area, and always keep your distance from places that it appears they may have settled in.

If you are attacked when it is hunting, its goal is going to be to subdue you so it can eat you. Like with other theropods, you can avoid it by sheltering somewhere it cannot reach you; it is not extremely large, so very sturdy vehicles might provide shelter if there are any nearby. Buildings with solid foundations and thick walls resistant to damage, or caves and crevices too small for it to fit into, are preferable to vehicles in any situation. Should it get its jaws around part of your body, fight back by striking vulnerable areas such as its eyes, nostrils, or the back of its throat. Defend yourself with anything you can use as a weapon; this species in particular lived in forested areas, so if any are brought to life again, their habitats will be full of tree branches you might be able to use as makeshift weapons. If you are able to get your attacker to back down, remain confident and retreat while keeping it in sight as long as you can. Once you are in the clear, get any bite wounds treated right away. Animals with serrated teeth often carry bacteria that can cause sepsis, which weakens the prey for the final kill.

In general, traveling in groups makes you a more difficult target, so a theropod may be less likely to attack if it sees you have numbers on your side. Always be cautious when traveling in the wild, keep a lookout for signs of animal activity, and give respectful distance to any animals you may see. If a predator approaches you, act confident and do not run; make it believe you are a challenge to kill, and it may choose something easier to eat.

Behind the Scenes

Vertebrate paleontologist Thomas R. Holtz, Jr. suggested in the late 1990s that the Metriacanthosaurus embryo portrayed in Jurassic Park was intended to be a Yangchuanosaurus, due to the fact that at the time Yangchuanosaurus was considered a species of Metriacanthosaurus and was featured on the cover of Gregory S. Paul’s Predatory Dinosaurs of the World. This book was used as reference material by both Michael Crichton and Steven Spielberg during development of the novel and film. Not all paleontologists ever agreed with this classification, though, and it was formally refuted in 2007.

Concept of a Yangchuanosaurus from the Jurassic Park Institute, which at one point suggested that this was the true identity of InGen’s Metriacanthosaurus

On page 95 of the Jurassic Park Institute Dinosaur Field Guide, the possibility of InGen’s Metriacanthosaurus being, in fact, Yangchuanosaurus shangyouensis is discussed. The book does acknowledge that the species might be M. parkeri, but the idea of it being “Metriacanthosaurusshangyouensis sensu Paul remained very popular among fans and paleontologists.

This was eventually disproven in 2014, when the Jurassic World website featured Metriacanthosaurus and explicitly described it as hailing from the Jurassic of England, rather than from the Jurassic of China. As of such, the species cloned by InGen is known to be Metriacanthosaurus parkeri.