Baryonyx walkeri (S/F)

Baryonyx (meaning “heavy claw”) is a genus of medium-to-large theropod dinosaur in the family Spinosauridae. It originally lived during the early Cretaceous period between 130 and 125 million years ago, during the Hauterivian and Barremian stages in what is now England. It was among the first piscivorous dinosaurs to be understood by paleontologists and known to the general public.

There is one recognized species of Baryonyx, called B. walkeri, which is named in honor of amateur fossil collector and plumber William J. Walker, who first discovered its remains. Walker found the remains, which initially consisted of a large claw, in January of 1983 in the Smokejacks Pit of the Weald Clay Formation near Ockley, Surrey, England. Returning to the clay pit to seek the claw’s missing tip, he also discovered a phalanx bone and part of a rib. His son-in-law brought the remains to the Natural History Museum of London, where paleontologists Alan J. Charig and Angela C. Milner inspected them. By June of that year, the entire skeleton had been uncovered.

A typical Baryonyx footprint. Image from the Dinosaur Protection Group

It took nearly six years to prepare the whole skeleton, but when this was finished, it yielded a body that was 65% complete, making it an excellent subject for study. The genus was named in 1986, midway through the skeleton’s preparation, when it became clear that it was an undiscovered type of theropod dinosaur. Its name, Baryonyx, refers to the size of its claws. It was originally assumed to be a dromaeosaur like Velociraptor, the claw being assigned to its toe; later, however, the claw was realized to belong to the finger.

Since its discovery, Baryonyx remains (mostly consisting of teeth) have been found throughout the United Kingdom and the Iberian Peninsula. The species Baryonyx tenerensis has been reclassified as of 1998 into a new genus, Suchomimus, leaving Baryonyx walkeri as the sole representative of the genus. It is understood to have been piscivorous, feeding on fish, because fish scales were found in its stomach; it is also believed to have fed upon land-dwelling animals such as Iguanodon.

Between 1986 and 1993, International Genetic Technologies succeeded in cloning Baryonyx walkeri from early Cretaceous ancient DNA obtained from gravid female mosquitoes preserved in amber samples. Further genetic research has gone into Baryonyx since then.

Mature form of the common variant of Baryonyx walkeri

Two distinct genetic lineages of Baryonyx have been produced by InGen. The more common version, which is presumed to be the older of the two, is defined by a wider, more flattened skull with less ornamentation, duller colors, and osteoderms on its body. The less common version generally resembles its fossil ancestor.

Baryonyx is among the larger spinosaurs, reaching lengths of 7.5 meters (25 feet) to 10 meters (33 feet) and growing to 2.5 meters (8.2 feet) tall at the hips. It weighs between 1.3 and 2.1 short tons, though InGen’s armored variant is likely a little heavier. The dinosaur’s most defining feature is the shape of its skull, which is highly elongated in a manner similar to crocodilians. In InGen’s older versions, the jaw tip is rounded and the skull is overall wider and flatter; the tongue is also rounded and cannot extend out of the mouth. In the newer version, the jaws are narrower and taller, more like the fossilized remains of this animal. Both versions bear crests; the older version has small ridge-like crests above the eyes, while the newer version has a small triangular sagittal crest above the eyes. The nostrils are placed farther back on the snout, and the eyes are average in size for a spinosaur with orange sclerae and round, bird-like pupils. This contrasts with Spinosaurus, which possesses slit pupils similar to those of crocodilians.

The snout is covered in sensory pits, which help it to detect movement in water. Older versions of Baryonyx have snouts ending in wide U-shapes, while the newer versions (much like fossil Baryonyx) have snouts which end in a spoon-shaped terminal rosette. This makes it somewhat resemble the modern gharial. These versions of Baryonyx show a dramatic S-shaped curve of the upper jaw, which is highly reduced in older genetic variants. The teeth are conical in shape and highly numerous (fossils have 76 to 78 teeth), designed to puncture the flesh of prey. These teeth vary in size, with the teeth near the front of the jaws being generally larger. This is especially pronounced in the newer genetic variants and fossil specimens. There is a rudimentary secondary palate dividing the oral and nasal cavities, similar to crocodilians; a rough, horny pad exists in the roof of the mouth.

Other hunting implements come in the form of Baryonyx‘s claws. The arms are not as thick or powerful as some other spinosaurs, but still make formidable weapons with their three-fingered hands ending in sharp hooked claws. The largest of these is the first finger, which bears a 31-centimeter (12-inch) curved claw. Its hands can be pronated, like most of InGen’s theropods, though artwork on the Jurassic World website appears to acknowledge that this is unlike the animals’ fossil ancestors. Its feet, like its hands, have three main digits; the fourth is a dewclaw, and it is a vestigial structure which no longer serves a purpose. While its legs are strong, it is not particularly speedy.

The main bulk of its body is rounded, with short, partially-overlapping cervical ribs similar to those of crocodiles. There is a short ridge down the spine. Its tail is long, constituting about one-third of its body length. The skin of Baryonyx is covered in rounded scales, with additional features varying based on version. Older versions show several rows of bony osteoderms like those of crocodilians extending from the neck to the end of the tail; newer versions lack these, and instead possess primitive protofeather quills on the skull and arms.

Coloration also varies between versions. The older version shows mainly cool, dull colors, with a blue-gray hue decorating the dorsal side and a lighter gray color on the belly, arms, most of the legs, and the sides of the face. Slightly brighter blue or teal color may be present on the snout and in speckles across the body, and a darker blue may ring the eyes. These colors are suitable for concealing the animal in a wetland environment. The newer version shows more vibrant color on the face, with the eye orbit and surrounding skin being a bright teal color and light yellow speckles on the snout. The rest of the body is a woody light brown or sandy tan color, with darker and lighter mottling across the entire body along with light yellow spots. The tail changes to a simple light-and-dark-brown alternating pattern. There is no obvious color to the protofeather quills. The mouth of the newer version is a brighter pink, as opposed to the dull color of the older version’s mouth.


Currently, little is known about the growth patterns and ontogenic changes of Baryonyx. A juvenile can be created in the mobile game Jurassic Park: Builder which more or less resembles a smaller version of the adult, but this portrayal differs slightly from the animal’s in-film appearance.

Subadult Baryonyx, distinguishable by their smaller size, appear in the virtual reality short film Jurassic World: Blue. The subadult of the old version, with the wider jaws and duller colors, appears very similar to the fully-grown adult. Meanwhile, the skeletal remains found near the scene more closely resemble the narrow jaws of the new version and fossil animals; it lacks the prominent notch of the jaws as well as the sagittal crest, suggesting that these features develop in adulthood.

A Baryonyx can reach adulthood by the age of eight. However, they reach sexual maturity before reaching skeletal maturity, and thus can breed before reaching full size. This is presumably with the use of growth hormones; fossil evidence suggests that sexual maturity was reached between 13 and 15 years of age, with at least one subadult specimen dying between the ages of 23 and 25.

Sexual Dimorphism

While the female of the older version has been positively identified, there is currently no reliable way to sex either version of Baryonyx.

Preferred Habitat

Since Baryonyx preys on fish, it prefers to live near sources of running water such as rivers or lakes. It has not yet been confirmed living in estuarine or marine environments: since the loss of clean fresh water in 2017 and 2018 was a major threat to its survival, it is unlikely that it has salt glands. Baryonyx also prefers cover in its habitat; forests may suffice, but it has been known to willingly move into confined spaces such as artificial underground tunnels to shelter.

The game Jurassic World: Evolution depicts it as requiring 7968 square meters of grassland, 504 square meters of forest, and 2868 square meters of wetland in its territory.

Isla Nublar

This spinosaur was originally planned for exhibition in InGen’s Jurassic Park during the late 1980s and early 1990s; however, it was never successfully introduced. Its paddock would have been located in the Eastern Ridge across the main tour road from a Dilophosaurus paddock to the west, separated from the road by a twenty-four-foot electric fence. It would have bordered a service road to the east with a similarly-sized fence, and the perimeter fences would have marked the northern and southern ends of its paddock.

Planned (orange) range of B. walkeri on Isla Nublar as of 1993

Sometime between September 2004 and May 30, 2005, any surviving Baryonyx from Isla Sorna were rounded up and transported to Isla Nublar. They would have had brief stays in a quarantine paddock before being introduced to their new habitats. Sometime after Jurassic World opened, the animals were introduced to a section of the Jungle River, where they were exhibited on the Cretaceous Cruise attraction. Population statistics for Baryonyx during this period of time are currently unknown. To prevent them from mingling with other dinosaurs to disastrous effect, these predators were restricted by technology, such as invisible fences and physical concrete barriers.

During Jurassic World’s preliminary developments, Baryonyx was included on a list of “most wanted” genera by Dr. Henry Wu‘s genetics department. This suggests that, as of 2004, genetic research was ongoing regarding this species (alternatively, it may have gone extinct on Isla Sorna before any could be rescued). Sometime by 2015, a new and more genetically pure Baryonyx was cloned by InGen. The Jurassic World website uses an illustration rather than a computerized render of the animal, suggesting that none had reached adulthood by that time. At least one subadult is known to have been visible in the Baryonyx exhibit, however.

A female Baryonyx of the older version was hatched sometime between May 16, 2009 and May 15, 2010; it was still believed to be alive as of May 15, 2018 at the age of eight.

On December 18, 2015, an incident occurred which resulted in the permanent closure of Jurassic World. Along with the other de-extinct animals, Baryonyx was no longer held back by invisible fence technology, and escaped its enclosure. Since the Jungle River provided them with sufficient habitat, many remained near it; however, they also claimed the maintenance tunnels as territory, sheltering there from any above-ground hazards. So far, none of the second version are known to have survived into mid-2018.

Between 2017 and 2018, the island’s volcano Mount Sibo became active. This threatened the Baryonyx population, as the Jungle River became polluted with sulfur dioxide and carbon dioxide outgassing, and harmful algal blooms occurred in the river. This killed off native and introduced fish, which dinosaurs such as Baryonyx relied on for food.

The virtual reality short film Jurassic World: Blue reveals that at least one male Baryonyx was living on the island prior to 2018, as a nest with six eggs was present in a volcanically-ravaged part of northern Isla Nublar early that summer. The skeletal remains of an adult Baryonyx were seen nearby, and one adult was seen guarding the nest. The surviving adult was killed before any of the eggs hatched, and none of the offspring are believed to have survived.

At least two Baryonyx lived in the area near Mount Sibo as of June 23, 2018. During the eruption which occurred on that day, a Baryonyx was forced into Radio Bunker 02-17 by lava, and died inside the bunker after being sealed in. A second was captured as it fled the eruption and transported off Isla Nublar via the S.S. Arcadia. Due to volcanic activity and loss of habitat, Baryonyx has probably become extinct on Isla Nublar.

Isla Sorna

InGen originally bred Baryonyx on Isla Sorna between 1986 and 1993. Population statistics are mostly unknown; at the time the island was abandoned in the summer of 1993, there were five living Baryonyx on Isla Sorna. They most likely inhabited the inner regions of the island, near the central channel where their food would be most plentiful.

Early versions of Jurassic Park /// show this animal living near the island’s airstrip.

Hypothetical (purple) range of B. walkeri on Isla Sorna as of 2001

Between 1998 and 1999, illegal cloning operations took place on Isla Sorna and introduced multiple new species to the island. These included a Spinosaurus, which would have competed directly with the Baryonyx for food. Its impact on their population is unknown at this time, but was probably disastrous for them.

By 2004, the island had entered a state of ecological collapse. While the Baryonyx would have avoided the worst of this due to feeding on fish as well as terrestrial animals, competition with the much larger and more aggressive Spinosaurus may have driven them closer to extinction. If any still lived as of late 2004, they would have been collected by Masrani Global Corporation and transported to Isla Nublar.


While Baryonyx is a capable swimmer, it would be very difficult for one to cross from Isla Nublar or Isla Sorna to the Central American mainland. However, human activity has brought them to North America in spite of the distance. While it is unknown if any Baryonyx were targeted by poachers between 1997 and 2018, an illegal retrieval operation that ended on June 23, 2018 captured Baryonyx for black-market sales.

Ken Wheatley, under the direction of Eli Mills, captured a Baryonyx as it fled the eruption of Mount Sibo and loaded it onto the S.S. Arcadia for transport to the Lockwood Estate near Orick, California. The animal was unloaded to the estate on the evening of June 24. It was sold to a Russian buyer, probably notorious mobster Anton Orlov (who had expressed interest in purchasing carnivores) and shipped to Russia via airplane. If any other Baryonyx were captured by Wheatley, they would have been released into the Northern Californian redwoods by Maisie Lockwood to save them from hydrogen cyanide poisoning.

Behavior and Ecology
Daily Activity

Baryonyx is believed to be diurnal, active mostly during the day. Some are known to prefer subterranean habitats, away from the normal cycle of night and day, which could cause them to adopt differing activity patterns than those which spend more time above ground.

Diet and Feeding Behavior

This animal is a carnivore, and is among the first dinosaurs discovered to have a partially piscivorous diet. Paleontologists have discovered stomach contents including scales from the fish Scheenstia mantelli as well as bones from a juvenile Iguanodon bernissartensis. Fossil evidence suggests that it used gastroliths to assist with digestion.

Skeleton of a Baryonyx, Isla Nublar 2018. Note the undeveloped skull features, indicating that this animal was not fully mature at the time of death.

The chief component of this animal’s diet is fish, which it captures live from water sources in its habitat. Baryonyx lives near rivers and lakes, though it has not yet been observed near estuaries or oceanic environments. It uses its strong jaws and conical teeth to capture prey, making rapid swishing movements with its snout to grab fish. When hunting, the snout of the Baryonyx is used to detect the movements of prey; its snout is covered in sensory pits which can help the animal discern where its prey is located and in what direction it is moving. This allows the Baryonyx to slyly ambush unsuspecting fish. Smaller prey can simply be swallowed whole, since it cannot chew; larger prey must be torn apart using the claws.

This is not a pursuit hunter, but it is capable of hunting on land as well as on riversides. Its legs are not built for fast running, so it probably hunts by ambush; its claws would be able to hook into small or medium-sized animals, delivering gashing wounds. Its teeth are evolved more for holding onto slippery prey, but its quick snapping bites would also be effective on land animals.

Like other carnivorous animals, it probably scavenges carcasses when it gets the chance. Its long snout would help it probe into the remains of dead animals to select choice pieces of meat.

Social Behavior
Guests view a Baryonyx on exhibit. This is presumably a stop along the Cretaceous Cruise attraction, where Baryonyx was housed.

This animal is able to live relatively near other members of its kind, but does not appear to be extremely social. It has been observed living alone, with some minor evidence that mated pairs may remain together over time. Particularly in InGen’s older version of Baryonyx, there are no display structures; the newer version has a head crest and quill structures, as well as brighter coloration, suggesting that it might be more social. However, very few of these are believed to have been created.

In the game Jurassic World: Evolution, a Baryonyx will become stressed if kept in groups; it may live alone or in a pair.


All dinosaurs lay eggs, and the Baryonyx is no exception. Their courtship behaviors are currently unknown, but assumed to be similar to those of crocodilians. Most known theropod species use cloacae as reproductive organs, and many exhibit monogamous behavior while breeding.

Baryonyx may exhibit monogamous behavior. A subadult parent Baryonyx was seen in 2018 nesting near the skeletal remains of another subadult Baryonyx, which may have been its mate. The sexes of individuals involved were unknown, but it suggests that both parents protect and care for their offspring. Curiously, the skull of the deceased individual appeared very narrow, much like the skulls of the newer versions; however, it lacked the prominent notch in the jaws or the sagittal crest, which may develop only once full maturity is reached. This suggests that the two versions are genetically compatible and can produce offspring. The viability and traits of the offspring are unknown.

Subadult Baryonyx defending its nest

The eggs of Baryonyx are roughly five to seven inches long, and like those of chickens, can be white or brown in color. They are slightly ovoid in shape, an evolutionary adaptation which prevents them from rolling too far from where they are laid. The parents will build a small nest out of mud or dirt, placing the eggs closely together inside. The clawed hands would be useful in constructing such a nest. Subadult parents may lay around six eggs. Breeding appears to occur in spring or early summer in the tropics, with a nest of eggs being observed in June on Isla Nublar, and the incubation period is probably around six months. The parents rarely venture far from the nest and defend it vigorously from predators, even those that are much larger than themselves.

In the cloned specimens produced by InGen, full size is reached in eight years or less, with sexual maturity reached before skeletal maturity. Fossil evidence suggests that without the use of growth stimulators, Baryonyx would instead reach sexual maturity at thirteen to fifteen years of age, reaching skeletal maturity at twenty-three to twenty-five or later.


Many of the Baryonyx‘s vocalizations are territorial in nature, since it is not an extremely social animal. It produces loud bellows and high-pitched screeches to intimidate rivals and enemies, as well as to establish dominance in its own territory.

It also uses non-vocal communications with its own kind. Various sources, including the Jurassic World: Fallen Kingdom Official Annual and the mobile game Jurassic World Alive, describe it splashing in water and clattering its jaws to communicate. The nature of these communications is not fully understood yet, but likely is used to share basic information about the environment and food sources, as well as displays during the mating season.

Ecological Interactions

Because it occupies a different ecological niche than many other larger theropods, Baryonyx is able to coexist peacefully alongside many of them. On Isla Sorna, its prey probably included bonitos, which are known to venture into the tidal rivers of the island. It would have competed for prey with the pterosaurs Pteranodon and Geosternbergia. The osteoderms of the Baryonyx would provide it with ample protection from these competitors’ attacks. By 2001, new carnivores including Spinosaurus and Ceratosaurus had moved into the island’s central waterway; these would have been more serious competition, particularly the huge fish-eater Spinosaurus.

Baryonyx in the wild on Isla Nublar, 2015-2018. Note the faint claw-mark wound on its left shoulder, evidence of a violent encounter with a deinonychosaur (probably Velociraptor or Deinonychus).

On Isla Nublar, Baryonyx was housed in its own enclosure on the Cretaceous Cruise, which also housed fellow spinosaur Suchomimus and the terrestrial hunter Metriacanthosaurus. Once the park was closed down, Baryonyx likely competed for prey with these animals. It is a moderately aggressive animal, not as fierce as Metriacanthosaurus, but managed to outlive this rival. Baryonyx moved into the island’s maintenance tunnels once it escaped its enclosure, helping it to avoid conflict with other carnivores. Potential territorial rivals in the north included Carnotaurus, Teratophoneus, Allosaurus, and Tyrannosaurus; the latter is known to have attacked and killed at least one Baryonyx. While rare, Velociraptor was also a threat as it would attempt to steal eggs. It probably did not have much to fear from the delicate omnivore Gallimimus other than possibly egg theft, and the tiny carnivore Compsognathus probably did not threaten it at all.

It lived alongside numerous herbivores on Isla Nublar as well. On the Jungle River, it would have neighbored Apatosaurus, Stegosaurus, Parasaurolophus, and Microceratus. Once it was released into the wild, it moved into the maintenance tunnels where it would seldom encounter herbivorous animals. Nonetheless, it sometimes came topside to hunt, particularly around the river. It is known to have lived in the area surrounding Mount Sibo, which could have had it encounter Pachycephalosaurus, Stygimoloch, Brachiosaurus, Ankylosaurus, Peloroplites, TriceratopsPachyrhinosaurus, and Sinoceratops. While it probably did not hunt these creatures as adults, it could have preyed upon their juveniles; fossil evidence suggests baby dinosaurs constituted part of its natural diet.

In the game Jurassic World: Evolution, it is susceptible to the rabies virus (Rabies lyssavirus); this is an infection which normally only affects mammals. According to the game, genetic modification has somehow made dinosaurs susceptible to this disease. In prehistoric times, it must have been affected by blood-drinking pests such as mosquitoes, as this is how InGen obtained its DNA. It is unknown if modern mosquitoes affect Baryonyx in a similar way.

Relationship to Humans

As the best-understood piscivorous dinosaur and the first spinosaur to be positively identified by paleontologists, the Baryonyx has been planned to appear in InGen de-extinction theme parks since the late 1980s. A section of paddock was set aside for it in Jurassic Park, though it was never successfully introduced to the Park before the incident that closed it down.

As a part of the 1994 cleanup process, a fluid specimen was obtained from a Baryonyx on Isla Sorna on

It is unknown if any Baryonyx survived on Isla Sorna until 2004, when its animals were relocated to Isla Nublar for use in Jurassic World. As of the summer of 2004, InGen’s Dr. Henry Wu was attempting to obtain more Baryonyx DNA samples, considering this among the most wanted genera for the new park. In any case, Baryonyx was successfully integrated into Jurassic World’s Cretaceous Cruise on the Jungle River, where it became a star attraction drawing in countless visitors. Eventually, a more genetically pure second version was engineered; there is only evidence of one being created, but it is likely more were at least planned.

Baryonyx also assisted with genetic research in Jurassic World in other ways. Its genome was utilized by Dr. Wu’s team to artificially evolve its close relative, Suchomimus. InGen had previously sourced the DNA of Suchomimus from North African amber, but this proved that genetic engineering could open up new routes for de-extinction and even species genesis.

After the park’s closure in December of 2015, Baryonyx‘s continued existence was put in peril. It was sometimes used by the Dinosaur Protection Group between 2017 and 2018 to advocate for de-extinct animal rights; an eight-year-old female Baryonyx was made symbolically adoptable on their website. This was one of several species intended to be rescued by the illegal June 2018 operation which the DPG’s founder Claire Dearing participated in. However, the supposed rescue operation ended up being a sham, with the dinosaurs intended for the black market.

DPG infographic featuring a Baryonyx

During the incident on June 23, a Baryonyx was driven by the eruption through the maintenance tunnels and into the recently-opened Radio Bunker 02-17. Once inside, it threatened Dearing and her associate Franklin Webb out of a combination of hunger and fear. It was wounded by molten debris as the humans made their escape, but it attempted to follow them out of the bunker; in order to protect themselves, Dearing and Webb were forced to seal the panicked animal inside the bunker. This caused the creature to burn to death.

A second Baryonyx was captured by mercenaries led by Ken Wheatley at the behest of Eli Mills. It was among the very last dinosaurs captured and loaded onto the S.S. Arcadia, and was transported to the Lockwood estate near Orick, California by the following evening. This Baryonyx was sold to Bidder 178 after sixteen bids for U.S. $21,000,000 along with a case of de-extinct animal DNA samples. Both were shipped out of the United States on board a Russian airplane, suggesting that the buyer was notorious mobster Anton Orlov. Previously, Orlov had expressed interest in purchasing two carnivorous dinosaurs to pit against one another in a death match, selling exorbitantly-priced tickets to spectators. However, there is no evidence that he was able to purchase any other animals, so it is unknown what he has done with his Baryonyx, which presumably still resides in Russia.

Based on Jurassic World: Evolution, the cost for raising a Baryonyx from fertilization to maturity as of 2018 would be $742,000.

Behind the Scenes
The Jurassic Park /// logo before Spinosaurus was introduced.

They are listed on the JP Brochure Map found in the Ford Explorer tour vehicles and on lab equipment on Isla Sorna. Baryonyx was originally slated to be the main star of Jurassic Park ///, but was eventually replaced with a larger, related species: Spinosaurus aegyptiacus.

The idea of using Baryonyx as the main antagonist is referenced in the film itself, with character Billy Brennan guessing that the animal which they encountered was a Suchomimus or Baryonyx before being corrected by Alan Grant. Its presence in the film canon has been known since 1993, with the animal’s icon appearing on merchandise and film production material. It would not be revealed until 2015, when artwork depicting it was featured on the Jurassic World official website; however, three years later when it actually appeared in Jurassic World: Fallen Kingdom, artists involved with the film chose to redesign the animal to make it appear more aesthetically Jurassic. This is to say that it was given a more outdated design, which drew complaints from scientific audiences, particularly as a very up-to-date design had been provided by paleoartists years before and was accepted.

Director Colin Trevorrow has suggested that the website design is paleoart in-universe, used instead of an image of the animals from the actual park for no explained reason. However, an image shared by Jurassic World social media depicts a Baryonyx that resembles the website art in the park itself, indicating that at least one individual that resembles this design existed in canon.

Notable Individuals

Auctioned Baryonyx – individual sold to a Russian buyer on the black market in 2018

Baryonyx – Isla Nublar – individual which inhabited maintenance tunnels; deceased in 2018

Grim – individual bred for Jurassic World

Chaos – individual bred for Jurassic World

Limbo – individual bred for Jurassic World