Deviations from the Real Dinosaur & Biology


The clones, like all of InGen's cloned theropods, had pronated hands. They were noticeably larger than the original animal. This can be seen in the broader skull[1] and its feet, which were so large that the soles of the feet were as big as a man[2] unlike the originals. The skull itself had exposed front teeth, a trait similar to an aligator and found in other cloned theropods, such as Ceratosaurus and Spinosaurus.

The cloned Tyrannosaurus had fully scaled skin as juveniles and as adults,[2] when it is considered by scientists that Tyrannosaurus was feathered at least some parts of its body. The Masrani backdoor gives a possible explanation that this could be due to the Null allele found in the cloned Velociraptor and Gallimimus created from the mutation and manipulation of dinosaur genes as well as the addition of frog, reptile, and bird DNA that causes feathered dinosaurs to have scaled skin.[3] Its skin was thick, being able to withstand the razor-sharp toe claws of a Velociraptor,[4] and the sharp claws of the hybrid Indominus rex that were able to debilitate a full grown Apatosaurus as well as the strong bite of the Indominus which was able to crack the bullet-proof glass of a Gyrosphere.[5] However, many of the adult Tyrannosaurs encountered by humans would bear at least one scar that would be found on their head or neck. Two adult males had a single scar on the side of their face.[2][6] The individual known as "Rexy" had several scars on her neck from a cloned Velociraptor that pounced on her.[5]

Sexual dimorphism was present in the recreated Tyrannosaurus, such as the males having a throat wattle and much more prominent brows.[7] The males also had deeper vocalizations than the females[2][6], though the female Rexy also had deepened vocalizations when she got older.[5] Every adult Tyrannosaur encountered each had their own unique skin color and pattern. Males tended to have a green skin color and females tended to have a brown color while the juvenile known as Junior was a mix of the two aforementioned colors.[8]

According to founder and former CEO of InGen John Hammond, the cloned T. rex could run at speeds of 32 mph.[4]

The clones seemed to have had an accelerated growth cycle as the Tyrannosaurus rex Rexy was the size of a 28-year-old when she was only three[9][10] and the only juvenile observed, Junior, was the size of a two-year-old tyrannosaurid yet was still highly dependent on his parents.[2]


As far as size goes, many different lengths and heights are shown in movie related material like posters and websites (see table). These values pendulate around the real-life estimates of the average T. rex. Many fans assumed these different sizes represent the sizes of the individual Tyrannosaurs seen in the films. However, there is no evidence for this connection.

Length Height Source
Jurassic Park related material:
12 m (40 ft) 6 m (20 ft) [11]
12 m (40 ft) 7.5 m (25 ft) [12]
12 m (40 ft) 6 m (20 ft) [13]
12 m (40 ft) 7.6 m (25 ft) [14]
The Lost World related material:
12 m (39 ft) 5.5 m (18 ft) [15]
10-12 m (33-39 ft) 4.3 m (14 ft) [16]
Jurassic Park III related material:
11.10 m (37 ft) 4.35 m (14.5 ft) [17]
11 m (37 ft) 4.5 m (14.5 ft) [18]
12 m (40 ft) [19]
11.3 m (37 ft) 4.4 m (14.4) [20]
Jurassic World related material:
4.6 m (15 ft) [21]
12 m (40 ft) 5 m (16 ft) [22]
12 m (40 ft) [23]
13.4 m (44 ft) [24]
13.4 m (44 ft) 5.1 m (16.8 ft) [25]


File:Tyrannosaurus Eating-1-.jpg

The clones were known to hunt prey by seeing movement,[4][2][6][5] which is currently unknown in the real Tyrannosaurus and might be an abnormality because the originals had excellent eyesight and sense of smell that aided them in hunting. According to in-universe paleontologist Dr. Alan Grant, the films' equivalent to the real Tyrannosaurus did indeed have motion-based vision,[4] though it is unknown if this was an accepted scientific fact in the film's universe or a theory or hypothesis. Another explanation for the motion based movement was frog DNA as this is stated by Phil Tippett, dinosaur supervisor for the first film[26] and the InGen Field Journal from Jurassic Park: The Game suggests this as well,[27] though it is disputed on whether JP: TG is within the same continuity with the films. When asked in an interview with Biography, Jack Horner, paleontological consultant for all the films, said in regards to the motion-based vision: [T. rexes] are like birds or any animal. If you stand perfectly still, there are very few animals who recognize you as a threat."[28]


From what has been observed of wild cloned Tyrannosaurus, they were solitary animals.[6] The only time more than one Tyrannosaur was seen together is when they formed families to raise their offspring.[2] There is fossil evidence that the real Tyrannosaurus rex were cannibals and they might have even roamed in packs, though none of these aforementioned behaviors have been observed with the clones. The cloned female Tyrannosaurus were known to be ambush predators.[4][2]

The cloned Tyrannosaurus rex were great parents to their young. They would usually have one offspring at a time who would stay in a nest while the parents would provide food for it for about 2 weeks until the juvenile learned to hunt on its own. If a Tyrannosaurus baby went missing, its parents would go search for it by hearing its cries or by smelling its blood. Even if they had retrieved their juvenile if Tyrannosaur parents smelled their offspring's blood on a potential threat they would confront it.[2]


The cloned Tyrannosaurus created by InGen reflect this level of intelligence in several instances. Rexy in particular has shown a good deal of intelligence during both the Isla Nublar incidents in both 1993 and 2015. In the former, she tested the electrical fences after the power outage, seemingly aware of the lack of power before attempting to escape.[4] During the incident in 2015, Rexy showed enough intelligence not to attack Blue during and after their fight with the Indominus, aware of key role the Velociraptor played in distracting the hybrid as it attempted to kill her.[5]

Both the male and female Tyrannosaurus during the Isla Sorna Incident in 1997 also showed a high degree of intelligence, seen in their efforts to protect their infant from the humans, even going so far as to push a trailer over a cliff and hunt in a familial pack.[2]



In the films, the non-cloned Tyrannosaurus rex apparently had motion-based vision. Whether this is a confirmed fact, a theory, or a hypothesis is unknown, but Dr. Alan Grant believed this to be true.[4]


Tyrannosaurus rex was created by InGen scientists in their compound on Isla Sorna[2][6] around 1990 or before.[9]

There has only been one Tyrannosaurus rex known to have been transported to Isla Nublar to live in Jurassic Park: an individual known as Rexy. She first arrived on the island in 1990 and lived in the Tyrannosaur Paddock of Jurassic Park.[4]According to, the paddock was originally designed to contain both an adult and a juvenile,[29] though it is unknown if a juvenile was ever transported to live there.

Isla Nublar Incident (1993)

Template:See The Tyrannosaurus rex Rexy was supposed to have been seen by InGen's endorsement team on their tour of Jurassic Park. However, despite attempts by Ray Arnold to lure her out of her paddock with a live goat, Rexy did not reveal herself to the visitors.[4]

When Dennis Nedry disabled most of Jurassic Park's security with Whte rbt.obj, Rexy was one of the dinosaurs that were able to roam the island freely. One of the embryos Nedry stole from the Cold Storage Room was Tyrannosaurus.[4]

After she ate the goat that was left for her, she attacked the endorsement team who were stranded near her paddock because of Whte rbt.obj disabling the power and even killed one of their members, Donald Gennaro. After pushing the tour vehicle of Lex and Tim Murphy off a cliff with Tim still inside the vehicle and Dr. Grant and Lex at the front of the car, she attacked Dr. Ellie Sattler and Robert Muldoon who were searching for the survivors at the time.[4]

In the morning, Rexy arrived in the Gallimimus Enclosure and killed an individual that lived there. Her next destination was the Visitor Center where inside she killed The Big One, a violent Velociraptor, and her remaining subordinate. This battle gave her scars on her neck,[4] which remained for the rest of her life.[5]

After the Isla Nublar Incident of 1993 Rexy became wild on Isla Nublar, probably living off surviving dinosaurs as a source of food and as a way to counter the Lysine contingency. Rexy remained this way for over a decade.[9]

Wild on Isla Sorna

The Tyrannosaurus rex on Isla Sorna became wild after Hurricane Clarissa struck the island. They were freed by either breaking out of their cages or by the workers on the island before they fled. To counter the Lysine contingency, T. rex and the other carnivorous dinosaurs ate herbivores who in turn ate lysine rich plants as one of their sources of lysine.[2]

Tyrannosaurus rex had varying levels of success on Isla Sorna. In the island's south, they were the apex predator of the region,[2] but in the north they were undermined by Spinosaurus.[6]

Isla Sorna Incident (1997) & San Diego Incident



A Tyrannosaurus rex family was involved in both the Isla Sorna Incident of 1997 and the following San Diego Incident. Their involvement began when the son was taken from the parents by InGen Hunters Roland Tembo and his hunting partner Ajay Sidhu so they could use him as bait to lure the father because Roland wanted to hunt a male Tyrannosaurus.[2] While the infant called for his parents to rescue, Peter Ludlow accidentally broke his leg while drunk when he was startled by the sound of an animal moving through the undergrowth.[30]

After the Gatherers freed the dinosaurs captured by the InGen Hunters, one of them named Nick Van Owen discovered the infant T. rex and his broken leg. He decided to take him back to his team's mobile labortory, where he and Dr. Sarah Harding fixed the juvenile's leg. However, his parents arrived after first aid was applied to the juvenile and cornered the RV. Dr. Sarah Harding realized that the two Tyrannosaurs weren't exhibiting hunting behavior so she convinced her fellow Gatherers to hand the young T. rex to his parents.[2]

The Tyrannosaurus parents put their child in a safe place, but they soon returned to the mobile lab to push it over a cliff. However, Eddie Carr saved his fellow Gatherers from falling with the RV, but soon afterward the Tyrannosaurus parents split him in half and ate him as he was trying to escape them. Even though the family was reunited, the Tyrannosaur parents traveled to the new camp of the Gatherers and the Hunters because they smelled the blood of their son on Dr. Sarah Harding's shirt. InGen Hunter Carter alerted his group upon seeing the Tyrannosaur Buck investigating the tent of Dr. Harding and Kelly Malcolm.[2]

While the Hunters fled, the Doe followed, killing many of them in the process. As the Tyrannosaur Buck continued his search, he was tranquilized by Roland Tembo. After the Tyrannosaur Doe's attack, Peter Ludlow ordered the remaining InGen Hunters to confiscate the Tyrannosaur Buck and recapture the juvenile T. rex for Jurassic Park: San Diego. But his plan went astray when the Tyrannosaur Buck escaped confinement upon reaching San Diego, California and went rampaging throughout the city, killing several civilians.[2]


To stop the chaos, gatherers Sarah Harding and Ian Malcolm broke into Jurassic Park: San Diego to steal the baby Tyrannosaur so they use him to lure his father back into the docks. The plan worked, but Peter Ludlow was killed by the Tyrannosaurs when he tried to recapture the juvenile. The Tyrannosaur Buck's rampage ended when Dr. Harding tranquilized him before the San Diego police could shoot him. Both Tyrannosaurus father and son were reunited once more with the female when they were transported back to Isla Sorna.[2]

Isla Sorna Incident (2001)

During his time marooned on Isla Sorna, Eric Kirby collected T. rex urine that he used to detour small carnivorous dinosaurs such as Compsognathus though he also learned that it attracted Spinosaurus as well.[6]

While a male was eating a Parasaurolophus[31], he encountered a group of humans consisting of Dr. Alan Grant, Udesky, Billy Brennan, and Paul and Amanda Kirby. They tried to avoid him by standing still, but the Tyrannosaurus rex noticed them and began to chase them. His chase of the humans ended quickly when he encountered a Spinosaurus, who was the first to pursue the humans. The two large theropods let out a loud roar as they initiated a fight. Unknown to the male, he nearly stepped on Dr. Alan Grant who was under him when getting into a stance just before the first strike in the conflict was made.[6]

The male Tyrannosaurus was the first to attack in the dual, biting down on the neck of the Spinosaurus and bringing it down to the forest floor. The Spinosaurus regained balance, however, and began to snap at his flanks, which he returned the favor. After the Spinosaurus swiped at him, the male decided to ram into his opponent head first. This turned out to have been a bad move for the Tyrannosaurus rex, as the Spinosaur was barely phased from the attack and then proceeded to bite down on his neck. As the male roared in agony, the Spinosaur, with support from its arms, proceeded to snap his neck. The Tyrannosaurus rex's body collapsed to the ground, nearly crushing Dr. Alan Grant while he was escaping. [6]

The Spinosaurus then claimed the corpse of its fallen foe triumphantly.[6]

Jurassic World

Template:See Rexy who had been wild on Isla Nublar for over a decade was captured sometime during Jurassic World's construction or years of operation to live as an attraction for the park, in particular, the T. rex Kingdom attraction.[9]

Though Rexy was the only Tyrannosaurus known to live in the park, there was a Cold Storage room for Tyrannosaurus present in the Hammond Creation Lab in the mid-2010s.[32]

Isla Nublar Incident (2015)

see Rexy

The base genome of the Indominus rex, the hybrid that caused the incident, was Tyrannosaurus rex.[5]

As the remaining members of the Jurassic World Velociraptor Pack fought the Indominus in Jurassic World's Main Street, the T. rex known as Rexy was released by Lowery Cruthers and lured to the fight by Claire Dearing per suggestion from her nephew, Gray Mitchell. The fight was going well until the Indominus overpowered the Tyrannosaurus. Right as the hybrid was about to kill her, the Velociraptor Blue, attacked the Indominus. With help from Blue, the Indominus was overpowered and thrown to the side of the Jurassic World Lagoon where the Mosasaurus residing there leaped out of the water and killed the hybrid.[5]

Behind the scenes

Jurassic Park


File:T-rex female.jpg

Mark "Crash" McCreery created the design of the T. rex that was used in the film. McCreery was working on Terminator 2: Judgment Day when the late Stan Winston moved him from that project to create sketches of the T. rex to generate interest in the film for Universal Studios.[33] His first drawing was of the T. rex running against a plain white background as a motion study. His second was of the T. rex in a jungle setting lifting its left leg high in an attack stance reminiscent of a bird of prey.[34] McCreery created the designs without a reference to go by, creating the drawings with what he remembered in his mind of then current information and new paleontological findings. After these sketches were done, Winston showed Steven Spielberg what McCreery had created and Speilberg gave his suggestions for the design of the animal. He felt that the design depicted in McCreery's drawings should have longer legs to hold the weight of it and that the feet were too small and bird-like. Speilberg also felt that the forearms looked weak.[33]

File:Snapshot 23.png

Several paleoartists were contacted in 1990, notably to design the T. rex. Among those consulted were Mark Hallett, Gregory S. Paul, and John Gurche. As his first assignment from production designer Rick Carter, Mark Hallet created concept art of the T. rex breakout. Afterward, Hallett created concept art of the Tyrannosaur's attack on the explorers and then storyboards of the Tyrannosaur's attack from the driver's side view of one of the tour vehicles. Finally, he created a character study of the T. rex.[35] Concept art of scenes featured of the T. rex by Craig Mullins,[36] David Negron,[37] John Bell,[38] and Tom Cranham,[39] resemble Hallet's design. Paleontologist Gregory S. Paul created skeletal and muscle studies of the Tyrannosaurus rex to be used as the base form of the dinosaur.[40][41] Paleoartist John Gurche also did concept art of the T. rex, these concepts being its anatomy and reconstructions that were accurate for its time.[42] Paleontologist Dr. Robert Bakker sent the filmmakers diagrams of Tyrannosaurus teeth, but according to Bakker "the powers that be didn't like the real tooth shape" and used a different, inaccurate design for its teeth.[43] The front facing eyes of the T. rex were kept by director Steven Spielberg because he felt it looked better when she was running toward the camera.[44]


Winston and McCreery would spend months redesigning the T. rex multiple times until a finalized design was reached.[33] When sculpting the 1/5 scale maquettes, Stan Winston and Mike Trcic spent time focusing on the design of the Tyrannosaurus' head, with the maquettes going through over thirteen different head designs as according to Paul Mejias, "[The dinosaurs] had to be perfect."[45] Trcic created several anatomically accurate T. rex head sculpts as a potential design, but this would go unused in favor of a broader head and exposed front teeth.[46] According to Gregory S. Paul, Trcic also used one of Paul's T. rex skeletals when designing the T. rex,[47] but director Steven Spielberg and Stan Winston ordered the dinosaurs to receive alternations from the current scientific knowledge of the dinosaurs Paul created skeletals for to copyright their designs, even though Trcic wanted to strictly use Gregory S. Paul's diagrams.[48][40][47] However, Trcic has said that after many arguments with Winston over the design of the T. rex, the T. rex design was "60% where [he] wanted it to be." McCreery then created another design of the T. rex based on what the maquette.[49]


Early concepts of the T. rex depicted her as having a green coloration with black striping.[37][39][50] The final coloration of the T. rex chosen for the first film was a dark brown color. McCreery explained that the reasoning behind this was because an animal as large as T. rex would not need camouflage and that the team feared that too strong of a coloration might make it look fake.[51] A green coloration would later be used for the males in The Lost World: Jurassic Park and Jurassic Park III.


The design that "Crash" McCreery first created would later be colored and used in promotional material for Jurassic Park and its sequel The Lost World: Jurassic Park.


Transition to CGI
File:T-Rex Animatic

Originally, most of the wide shots of the dinosaurs were to be portrayed by go motion animation created by Phil Tippett.[52] With consultation from Mark Hallett,[53] Stefan Dechant had created digital animatics featuring a computer generated T. rex, but these were replaced by the go motion animatics created by Tippett Studio.[54] An animatic was even created of the breakout sequence featuring the go motion T. rex. Tippit and his team sent Spielberg animation tests of Tyrannosaurus and Velociraptor. Though a motion blur was added to the make the stop motion dinosaurs more realistic, Speilberg felt that the movements of the dinosaurs were still jerky. Dennis Muren then suggested to Speilberg that Industrial Light and Magic create computer generated full-sized dinosaurs. Interested, Speilberg requested a test be made featuring CGI dinosaurs.[52]

File:Clay motion rex.jpg

After ILM created a herd of Gallimimus skeletons running,[52] Steve 'Spaz' Williams with support and assistance from Mark AZ Dippe, his friend and confidant, created a running Tyrannosaurus skeleton during off-hours and in-between assignments at ILM. The reference he used for the skeleton came from page 341 of Gregory S. Paul's 1988 book Predatory Dinosaurs of the World.[55]

Speilberg was not fully convinced to use CGI for the dinosaurs until ILM made more tests featuring a fully fleshed T. rex and said T. rex chasing a herd of fully fleshed Gallimimus.[52] This skin was rendered by Stefan Fangmeier.[56] Though the dinosaurs were to be now CGI in the film, the stop motion animatics and tests would be used as a reference for the animatronic dinosaurs.[57]


A full-sized Tyrannosaurus animatronic was created by Stan Winston Studio for the filming of the dinosaur's breakout. Taking two years to make, the animatronic was the first animatronic to be mounted on a motion simulator to achieve gross body movements and at the time was the largest animatronic the studio ever produced[58] only being surpassed by the Spinosaurus animatronic created for Jurassic Park III.[59] Powered primarily by hydraulics,[60] a 1/5 scale telemetry device shaped like the dinosaur was used to provide the movements of the full sized animatronic[57] with the eyes being radio controlled.[61] Another animatronic was also used for shots of its feet that was an underbelly on a rolling platform with hydraulic legs and tail.[61][62] Another prop was a separate head with extra detailing and added mechanics used for close-up photography.[61]

There had been plans to create a full-sized sleeping T. rex that was later conceived as a miniature when Stan Winston proposed to the studio that the money that was to be used for this animatronic be used to create the full-sized Tyrannosaurus instead until the sleeping T. rex was scrapped altogether.[63] Concept art was even created by "Crash" McCreery of this cut prop.[64] Stan Winston Studio also considered using a 1/5 scale rod puppet before the full-sized animatronic was conceived.[63] This concept would later be put to life for the sequel Jurassic Park III, but only as a test.[65] Speilberg had also originally wanted the animatronic Tyrannosaurus to be a freestanding and that was able to walk until it was discovered that it was not possible and he realized how impractical it would be.[66]

The animatronics were filmed on set at Warner Brothers Studio Stage 16.[67] For the filming of the attack sequence, the animatronic with legs [62][57] and the insert head were used. The insert head in particular was manipulated by a highly poseable hydraulic powered crane as well as man-power.[68]

There were troubles while filming the scene as both the animatronics began to shiver due to their latex skin absorbing the rain,[57] requiring the crew to dry the animatronics down after every shot.[69] Filming also received a major setback when the head-turn cylinder of the full-sized animatronic broke, though this was quickly repaired.[70] Overall, shooting of the scene was finished four days ahead of schedule.[71]

Change of Ending

In the original endings for Jurassic Park, one raptor was to be crushed by one of the falling skeletons while the other would either be moved and crushed to the jaws of the T. rex skeleton by Dr. Grant using a crane or by Hammond shooting the raptor.[72][73][74] Another ending would have also featured Hammond coming killing the first raptor with a bazooka while Dr. Grant used a crane to kill the remaining raptor like one of the other ending.[75]Rexy was even scripted to die like her novel counterpart at one point.[76] These endings and her death were scrapped from the film because Spielberg believed the T. rex to be the star of the film alongside the smaller Velociraptor.[73]

Finishing Touches

Phil Tippit worked with ILM in post production to create the dinosaur input device or DID for short; an armature like that seen in go motion models that could be manipulated by Tippit and his team of stop-motion animators.[77] Out of the four DIDs created, two were for T. rex while other two were for the raptors.[78] The T. rex DIDs was only used for the road attack sequence while ILM created the rest of the shots featuring T. rex as Tippitt's team and ILM were originally going to work together until it was decided that both would be split into two teams.[79]

The digital model for the T. rex received several changes from Speilberg that differed from the animatronic, these changes being a different arm length, larger and stockier feet, and a more streamlined jaw as well as adjustments to her eyes.[44]

Years later, ILM would modify the T. rex model for lip sync tests for the 1996 film Dragonheart.[80]


The female roars were created from crocodiles, lions, alligators, dog, penguin, tiger, and elephant layered together.[81][57] Whale blowholes were also used looped to create the sound of the dinosaur breathing.[81] The sound of Rexy as it kills the Gallimimus was simply Rydstrom's dog, a Jack Russell Terrier named "Buster",[82] playing with a rope toy.[52] The footsteps of the T. rex were of redwood trees being cut down and falling to the ground.[57]

The iconic high-frequency "scream" originates from a baby elephant that Gary Rydstrom and his team recorded. It was only recorded once creating this sound and the team tried to get the elephant to create the sound again, but it refused to do so. Because of this, Rydstrom used the same elephant sound for each take.[83] This elephant sound was used for mid-range frequencies with an alligator's growl and tiger's roar added.[81]

The Lost World: Jurassic Park


For the The Lost World: Jurassic Park, a female, male, and juvenile Tyrannosaurus were set to appear in the film.

In the digital storyboards by Stefan Dechant the male was depicted as either yellow and gray or as the same color as the female.[84] John Rosengrant later devised the green color scheme for the male.[85] One such concept by Rosengrant was a colored version of the 1991 T. rex concept art for the first film.[86] Another color scheme applied to this same concept art would be widely used in promotional material for the film. Even though the Buck was given a different skin color to differentiate it from the female, Stan Winston Studio was concerned that this would be difficult to see in low-light conditions. So Shane Mahan began to manipulate images of the T. rex from the first film, creating a series of eight head designs that he sent to Speilberg. The design chosen by Speilberg featured larger brows, a scarred face, and a neck wattle.[7]

Joey Orosco created the concept art for the juvenile.[87] The juvenile went through many changes in his color scheme, such as one of his maquettes depicting him as brown,[88] another maquette depicting him as bright green,[89] and one paint scheme of his animatronic depicting him as a duller green.[90] However, evidence in the film and promotional photos of the animatronic suggest that Junior is actually a mix of brown and green.[91]

The female also received a new skin color as well, her skin being lighter than the previous female that appeared in the first film.[8] However, promotional material depicted her as a darker brown and sometimes with a bluish tent to her head.



For close-up shots in the film, two animatronics were used to primarily to depict the tyrannosaur parents using the armatures of the full-body animatronic and insert-head of the first T. rex, the female in particularly using the insert-head armature. Unlike the first full-sized T. rex animatronic, the animatronics for the parents was from head to mid-torso with arms and were mounted on rail powered dolly carts.[92] This was done because Stan Winston Studio discovered there no need to make a full sized animatronic like in Jurassic Park as the audience only the head and half the body could be seen. Furthermore, the carts provided more mobility and freedom when compared to the motion platform.[93] The most notable usages of the animatronics were when the parents approach the trailer and when they attack Eddie Carr.[94]

Two animatronics were used to portray the juvenile. One was a mixture of hydraulics and cables used when he was laying on his side while the other was remote controlled and used when someone was carrying him.[94]

From Pteranodons to San Diego

In one of the original endings for The Lost World: Jurassic Park, Pteranodon or Geosternbergia (then classified as a species of Pteranodon) were to attack the rescue helicopter at the end of the film.[95] While at his vacation home in the Hamptons for the Fourth of July, director Steven Spielberg suddenly saw an image in his mind of a boy looking out of his bedroom to seen a T. rex drinking from the family swimming pool. Prompted by the image he saw, Spielberg changed the ending to what is seen in the completed film[96] and included the image he saw as the scene where the Buck approaches the house of young Benjamin and his family.

In one concept of the T. rex being transported, it appears the mother was to be captured instead of the father as this T. rex is brown instead if green.[97]


For the male, pigs and "weird Costa Rican mammals", mammals that Gary Rydstrom and his team recorded but never knew what their identities were, had a similar screech like the baby elephant used for the females and were used in place of the latter. The juvenile's vocalizations were of a baby camel crying for its mother.[95] The original T. rex roars were also reused for the female.

Jurassic Park III

The Replacement

In early logo designs for the film, Tyrannosaurus was to be featured like in the previous two films. Many of the logos had the same T. rex design used in the logos for the previous films, but there were different designs exhibited in the preliminary logos such as the T. rex with a more widened mouth,[98] the T. rex more upright and looking straight ahead,[99] and a full skeleton of T. rex roaring.[100]

For Jurassic Park III, the filmmakers wanted to have another dinosaur to replace Tyrannosaurus from the previous two films[101] and searched through many candidates in the process.[102] Eventually Spinosaurus was chosen after Paleontologist Jack Horner suggested Spinosaurus to the filmmakers as a replacement[103] and from the discovery of a Spinosaur skull during the pre-production of the film.[59]

Rod-puppet Test

During early development of the film, Stan Winston Studio created a 1/5 scale rod-puppet T. rex. They filmed this rod-puppet in forced perspective to create several tests to see if they could prove a concept that would work.[65] This rod-puppet would ultimately go unused in the film.

The Battle


Director Joe Johnston created the famous Spino vs T. rex as an homage to Ray Harryhausen's go motion dinosaurs and wanted to recreate a modern version of those fights.[104] In one draft of the script the carcass the Tyrannosaurus was eating was a sauropod[105] when the actual prop used in the film is the Parasaurolophus carcass used in The Lost World: Jurassic Park repainted[106] and the carcass itself is left unidentified in the film.


For the battle, the animatronic of the Buck was refurbished.[107] Due to how powerful the mechanical Spinosaur was, the Spino destroyed the Tyrannosaurus with one final blow that broke its neck which in turn caused its head to collapse, releasing hydraulic fluid that John Rosengrant described as being "almost like blood spewing". Rosengrant further described the destruction of the animatronic as "[A] really sad ending to a long night of shooting".[59] Over 20 seconds of footage of the fight, particularly of the animatronics, was cut from the film.[108] Despite this, a shot of the animatronic fight where the Spinosaur slaps the Tyrannosaur was still present in the theatrical trailer.[109]

For the CG T. rex, the model of the Buck from the previous film was reused with some updates. New geometry was created for its surfaces so that it would work better in ILM's simulations. New animation controls were added as well that were up to date at the time the computer graphics were created for the film and the model's UV Maps were reworked, though originally the ones from The Lost World were to be used.[110]


The battle is very controversial among fans of the franchise due to the fact that the T. rex, which had been well received by many fans, lost the battle. For more details on who would win a fight see the article Spinosaurus vs. T. rex Scene. The destruction of the mounted Spinosaurus in Main Street from the Tyrannosaurus Rexy in the fight at the end of the fourth film Jurassic World is a reference to this infamous fight.

When a fan on Twitter sent Jurassic World director Colin Trevorrow a link to a Facebook fan group petitioning for a rematch between the two theropods, Colin replied "Noted, my friend."[111]

Was the JPIII Rex a Sub-Adult?

It is popularly believed that this Tyrannosaurus was a sub-adult due to JPIII size charts giving lower size estimates than that of previous size estimates given to Tyrannosaurus rex of the franchise and because it had a brighter coloration than that of the Tyrannosaur Buck, a fully grown adult male.[112] However, there are problems with this theory. Regarding skin color, every tyrannosaur in the films has their own unique skin color and the Tyrannosaur Doe, an adult, has lighter colored skin than Rexy who is an adult as well.[8] As for size, size is inconsistent in the films and their supplementary material. Furthermore, since there has been no official source found or released thus far that confirms that this individual was a subadult its smaller size could be something else instead of just simply being a subadult. It can be noted that size can vary within a species and that there have been individuals of a species that can grow smaller or larger than the average size given for that said species.

Jurassic World


Jurassic World saw the return of the Tyrannosaurus Rexy, the T. rex that appeared in Jurassic Park. Director Colin Trevorrow described the film "This is [the Tyrannosaur's] Unforgiven."[113] The T. rex model was created by Steve Jubinville and the director aimed to make the model look as close as possible to its design in the first film.[114] The Jurassic World Tyrannosaurus was made to look older by giving her the scars she received from the end of Jurassic Park as well as tightened skin. The T. rex was primarily portrayed with performance capture technology rather than life-sized animatronics.[113]

Cultural Impact

The design of the film's Tyrannosaurus is a notably popular way to depict Tyrannosaurus in media. The silhouette of the T. rex from the Jurassic Park III size chart was even used in a now-defunct BBC Nature article about dinosaurs.[115]

Mike Trcic expressed disappointment with the popularity of this design in an interview with Shannon Shea (who worked with Trcic on Jurassic Park). In the interview, he said regarding how popular the design had become, “Whenever I search Google images for a Tyrannosaurus Rex [sic], most of the art I see is based on the original JP Rex. It’s a shame that people just accept that somehow it IS what a T-Rex [sic] looked like. It’s limiting because unless someone can travel back 65 million years, how can anyone be completely sure?”[116]

The vocalizations that were created by Gary Rydstrom are also a popularly used sound effect. Jurassic World sound designer Al Nelson said in regards to how famous its roars were in the films: "The T. rex is one of the most iconic sounds in all of film history. Every sound designer knows it. Almost any kid knows it. When you hear it you're like 'That's the T. rex!'"[117]


Tyrannosaurus, Triceratops, Velociraptor, and Parasaurolophus have appeared in all four films thus far.

Notes and references

  1. Hallet, Mark. (Spring 2013) "Sketch me a Spitter! An Artist Remembers Jurassic Park". Prehistoric Times Magazine, 105, p. 48
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 The Lost World: Jurassic Park
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 Jurassic Park
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Jurassic World
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 Jurassic Park III
  7. 7.0 7.1 The Making of The Lost World: Jurassic Park by Don Shay and Jody Duncan, pp. 45-46
  8. 8.0 8.1 8.2 Comparison between Rexy, (young and old) the Buck, the Doe, Junior (additional shot), and finally, the Jurassic Park III T. rex.
  9. 9.0 9.1 9.2 9.3 The Tyrannosaurus Rexy, according to, had lived on Isla Nublar for 25 years, so Tyrannosaurus was probably recreated around 1990 or before. This also means that Rexy would have been 3 years old of age at time of the Isla Nublar Incident of 1993.
  10. Jurassic World director Colin Trevorrow as well as Industrial Light and Magic members Geoff Campbell and Steve Jubinville have stated that the T. rex from Jurassic World was indeed the same individual that appeared in Jurassic Park.
  11. Sizes of the full body T. rex animatronic. Length size from Stan Winston in the documentary The Making of Jurassic Park and height from the Behind the scenes website.
  12. Jurassic Park Sourvenir Magazine, page 38, picture.
  13. Size chart, source unknown.
  14. Jurassic Park Topps trading cards #1, #33
  15. The Lost World: Jurassic Park-DVD/Extra Features/Dinosaur Encyclopedia/Tyrannosaurus
  16. The Lost World: Jurassic Park Educational Resource Guide
  17. Jurassic Park III size chart poster (metric sizes from German version), picture.
  18. Jurassic Park III-DVD/Bonus Materials/Dinosaur Turntables/Tyrannosaurus (imperial sizes only)
  19. Inkworks Jurassic Park III Premium Trading Cards #56
  20. Jurassic Park III Dino Scaler (Polish)
  21. 50px Infographic from the Innovation Center.
  23. RaptorPass 8 Tyrannosaurus rex
  24. Jurassic World: Where Dinosaurs Come to Life, page 14.
  25. The Park is Open
  26. Phil Tippett (2014). Phil Tippett Interview - 5th February 2014,, Feb 5, 2014.
  27. InGen Field Journal, Tyrannosaurus rex
  28. Cohn, Paulette. (June 12, 2015) Jurassic World's Dinosaur Expert Talks Facts vs. Fiction (INTERVIEW). Biography
  29. 50px
  30. The Lost World: Jurassic Park Deleted Scene
  31. CG Supervisor of Jurassic Park III Christophe Hery identifies the carcass as Parasaurolophus. Furthermore, the prop used is the carcass from The Lost World: Jurassic Park repainted.
  32. Jurassic World - Inside the Hammond Creation Lab (HD)
  33. 33.0 33.1 33.2 Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 48.
  34. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 20
  35. Hallet, Mark. (Spring 2013) Sketch me a Spitter! Prehistoric Times Magazine, 105, pp. 47-48
  36. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 7
  37. 37.0 37.1 The Making of Jurassic Park by Don Shay and Jody Duncan, p. 9
  38. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 13
  39. 39.0 39.1 The Making of Jurassic Park by Don Shay and Jody Duncan, p. 10
  40. 40.0 40.1 Gregory S. Paul: The Full Autobiography Part 4.
  41. Curriculum Vitae - Gregory S. Paul: Books, Articles, Abstracts & Other Projects.
  42. Kartzman, Mark. John Gurche Interview Artzar (archived from the original)
  43. Kushner, David. (January 17, 2012) Meet the Scientists Who Make Science Fiction Believeable. Popular Mechanics.
  44. 44.0 44.1 - Interview: ILM on Jurassic World (February 3, 2016) Retrieved from
  45. Duncan, Jody. (December 15, 2012) Jurassic Park's T-Rex - Constructing a Full-Size Dinosaur. Stan Winston School, excerpted from The Winston Effect: The Art and History of Stan Winston Studio.
  46. Hallet, Mark. (Spring 2013) Sketch me a Spitter! Prehistoric Times Magazine, 105, pp. 48
  47. 47.0 47.1 Morales, Bob. (April/May 1999) The PT Interview: Gregory S. Paul Part I. Prehistoric Times, 35, p. 10. Retrieved from
  48. Paul, Gregory S. (Fall 2013) A Little More On Jurassic Park. Prehistoric Times, 107, p. 46
  49. Michael Trcic Discusses Creating the Jurassic Park T-Rex. YouTube
  50. Hallet, Mark. (Spring 2013) Sketch me a Spitter! Prehistoric Times Magazine, 105, p. 49
  51. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 73.
  52. 52.0 52.1 52.2 52.3 52.4 The Making of Jurassic Park documentary
  53. Hallet, Mark. (Spring 2013) "Sketch me a Spitter! An Artist Remembers Jurassic Park". Prehistoric Times Magazine, 105, pp. 49
  54. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 52.
  55. Failes, Ian. (April 4, 2013) Welcome (back) to Jurassic Park. fxgudie.
  56. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 137
  57. 57.0 57.1 57.2 57.3 57.4 57.5 Return to Jurassic Park: Making Prehistory
  58. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 104
  59. 59.0 59.1 59.2 Duncan, Jody. (September 29, 2012) Jurassic Park III's T-rex Killer: Spinosaurus. Stan Winston School of Character Arts.
  60. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 72, p. 73.
  61. 61.0 61.1 61.2 The Making of Jurassic Park by Don Shay and Jody Duncan, p. 31
  62. 62.0 62.1 The Making of Jurassic Park by Don Shay and Jody Duncan, p. 107
  63. 63.0 63.1 Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 72.
  64. Jurassic Park Topps trading cards: #84 - Sleeping Tyrannosaurus
  65. 65.0 65.1 JURASSIC PARK III T-Rex Rod Puppet Tests & More.
  66. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 48.
  67. The Making of Jurassic Park by Jody Duncan, p. 106
  68. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 76.
  69. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 111
  70. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 79.
  71. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 112
  72. Return to Jurassic Park: Making Prehistory
  73. 73.0 73.1 The Making of Jurassic Park by Don Shay and Jody Duncan, p. 118.
  74. Sharpio, Mark. (1993, August) In the Shadow of the Dinosaurs. Fangoria, 27. Retrieved from
  75. Freer, Ian (October 8, 2014) Steven Spielberg And Special Effects. Empire.
  76. Nerdist Podcast - Episode 772: Kathleen Kennedy (December 16, 2015) Retrieved from
  77. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 132
  78. Duncan, Jody. (1993) Beauty in the Beasts. Cinefex, 55, p. 58.
  79. The Making of Jurassic Park by Don Shay and Jody Duncan, p. 133
  80. Failes, Ian. (May 31, 2016) An Oral History of ILM’s ‘Dragonheart’ On Its 20th Anniversary. Cartoonbrew.
  81. 81.0 81.1 81.2 The Making of Jurassic Park by Don Shay and Jody Duncan, p. 144
  82. Buachann, Kyle. (June 9, 2015) You’ll Never Guess How the Dinosaur Sounds in Jurassic Park Were Made. Vulture.
  83. Sullivan, Becky. (April 13, 2013) Jurassic Bark: How Sound Design Changed Our Imaginations. NPR
  84. The Making of The Lost World: Jurassic Park by Don Shay and Jody Duncan, p. 26
  85. The Making of The Lost World: Jurassic Park by Don Shay and Jody Duncan, p. 47
  86. Mark “Crash” McCreery and John Rosengrant T-Rex artwork from The Lost World: Jurassic Park II
  87. The Making of The Lost World: Jurassic Park by Don Shay and Jody Duncan, p. 25
  88. Making the 'Lost World'
  89. 50px
  90. Twitter@SWinstonSchool From concept art to the real thing (with a lot of hard work in between by amazing artists) #30daysofdinosaurs. (June 14, 2016)
  91. 50px50px50px
  92. The Making of The Lost World: Jurassic Park by Don Shay and Jody Duncan, p. 46
  93. Duncan, Jody. (May 29, 2012) The Lost World Jurassic Park 2's T-rexs. Stan Winston School of Character Arts, excerpted from The Winston Effect: The Art and History of Stan Winston Studio.
  94. 94.0 94.1 Return to Jurassic Park: Finding The Lost World
  95. 95.0 95.1 Return to Jurassic Park: Something Survived (...and came to San Diego)
  96. The Making of The Lost World: Jurassic Park by Don Shay and Jody Duncan, pp. 71-72
  97. 50px
  98. 50px
  99. 50px
  100. 50px
  101. The Making of Jurassic Park III
  102. Return to Jurassic Park: The Third Adventure
  104. Berry, Mark F. (January 1, 2005) The Dinosaur Filmography, p. 172. (Google Books) Retrieved from
  105. Jurassic Park III film script: Scene 40: Int. Plane
  106. This can be proven due to it having exposed ribs like the dead Parasaurolophus made for TLW and has a greenish skin color with a dark green splotch on its back like the repainted latter.
  107. Jody Duncan writes that the T. rex animatronic was simply one of the Tyrannosaurus built for The Lost World: Jurassic Park albeit refurbished. The identity of the TLW Tyrannosaur that was reused for Jurassic Park III is the Buck due to the presence of a scar on the side of its face, neck wattle, more prominent brows, and bearing dark yellow striping on its neck and upper back.
  108. Goldwasser, Dan. (July 9, 2001) Don Davis - Interview.
  109. Youtube - Jurassic Park III (2001) Theatrical Trailer
  110. Deckel, Larry. (October 2001) Jurassic Park III: Bigger, Faster, Meaner. Cinefex, 87, p. 37.
  111. Twitter - Colin Trevorrow
  112. (Archived October 19, 2015, First posted May 2, 2013) Sub-adult Tyrannosaurus (S/F). Jurassic Park Legacy.
  113. 113.0 113.1 Sciretta, Peter. (April 29, 2015) Original T. rex Returns in ‘Jurassic World,’ This Film “Is Her Unforgiven”. Slashfilm.
  114. Jurassic World
  115. Dinosaurs.
  116. Shea, Shannon. (June 11, 2015) How We Made The Iconic T-Rex of Jurassic Park. Filmschool Rejects.
  117. Making Tyrannosaurus Rex Sound. Youtube