Tyrannosaurus rex animatronic (The Lost World)

For The Lost World: Jurassic Park, a full scale animatronic of a male Tyrannosaurus rex was built and designed, alongside a female animatronic.

The same male animatronic would be reused in the 2001 sequel, Jurassic Park III, and was slated for use in the infamous duel with the Spinosaurus, where the T. rex animatronic would be destroyed in the fight. Ultimately, its use would be relegated to a few seconds within the film.

Design
Taking inspiration from nature, John Rosengrant colorized old Jurassic Park line-art from Mark McCreery of a male counterpart to the female Tyrannosaurus rex. Main concerns from Shane Mahan was that the color could be drowned out in night sequences, which a majority of the Tyrannosaurus scenes would take place in.

Eventually, a mottled green base coloration was supplemented with dark and yellow striping on the upper contours–along the spine–with whitish or cream underbelly. To further the sexual dimorphism between the two genders, alterations to the head and neck design were made. A total of eight different design choices were presented by Shane Mahan to director Steven Spielberg for the latter’s approval. The final chosen design included a neck wattle, bonier face, and a scarred muzzle.

The Lost World: Jurassic Park
Instead of designing a whole new mold for the male, additions were made to the original epoxy of the Jurassic Park Tyrannosaurus mold in order to cast the new skull. Due to budget issues as well as cinematic preference, it was deemed more economic to construct the Tyrannosaurus from the thigh and up, as a majority of the shots of the animatronic during the filming of the first movie did not show the tail or lower legs.

Much like the animatronic from the previous film, the male dinosaur was controlled via telemetry device, which gave the crew better control of the armature. However, unlike the animatronic from the previous film, the T. rex was built on a cart that ran along an eighty foot long track, on which the 18,000 pound animatronic could travel between five and eight miles per hour. On the cart, the animatronic could rear up to twenty feet in height and stretch out to thirty-seven feet long. Because of the size of the animatronics, they were incapable of being moved from their track once on set, and so the set had to be built around it.

Learning from past mistakes, Stan Winston Studios created a foam rubber skin coated with silicone rather than a pure foam latex skin. This better waterproofed the skin, an issue during the first film, for the trailer sequence, which occurred during a torrential downpour.

Finally, the animatronic was also required to interact with a stunt double, requiring the need for precision and delicacy for sake of the actor's safety. During a sequence in which the T. rex would have to rip Eddie Carr (Richard Schiff) out of his SUV, a specially designed suit was made for Schiff’s double to be worn during the shot. The animatronic had the capability to easy kill a human being if it were to malfunction or did not have the requisite finesse. Stan Winston made special note of this to the crew during the trailer sequence preparations.

Jurassic Park III
The Tyrannosaurus would play a minimal role in the third Jurassic Park film, and thus, there was no need to build a new animatronic. Instead, the male animatronic from The Lost World: Jurassic Park was brought out of storage, then cleaned and repainted for use. The Spinosaurus and Tyrannosaurus fight was the final scene filmed with the Spinosaurus animatronic, and the Stan Winston Studios crew decided to go all out in the battle.

The crew had the puppets act out as if they were fighting a real battle, and during the fight, the Spinosaurus' superior powerful hydraulics allowed the Spinosaurus to literally behead the Tyrannosaurus animatronic with a single swipe from its clawed arm.

In the end, the animatronic was utilized for two scenes in the film, those being its first and last appearance, where it's seen rearing up and roaring, and on the ground, deceased, respectively. It was originally intended to have a larger role in the film, with a few short scenes being cut. These involved the two battling robotic creations being seen sizing each other up, and the Spinosaurus breaking the deadlock by smacking the T. rex in the face. This deleted sequence can be seen in behind the scenes featurettes and certain trailers for the film, as well as many production screenshots.

Sound design
In The Lost World: Jurassic Park, Gary Rydstrom and the sound effects team sourced from different animals to make the male Tyrannosaurus roar deeper than the females. Sounds for the male included, pigs and some other “weird Costa Rican mammals that [they] didn’t even know what they are.”

Instead of using the baby elephant rumbles and squeaks that were the base for the female T. rex bellow (and continued to be the base for the female in The Lost World: Jurassic Park), the male’s roar are made up of all “baby elephant-like” sound recordings that were twisted to mimic the sounds of the female's roar. However, the rest of the roars that were mixed into the T. rex vocalizations were the same for both genders (tiger, alligator, and dog vocals).