A popular fan theory is that this animal becomes the Sub-Adult Tyrannosaurus that battles the Spinosaurus in 2001, but there is no evidence to support this line of thought. The Infant Tyrannosaurus was the male and only known offspring of a female Tyrannosaurus and a Male Tyrannosaurus that was involved in events that transpired on Isla Sorna and San Diego, California in 1997. Up to the point that the Hunter’s Expedition came to Isla Sorna, the animal often stayed in the Rex Nest, where his parents would bring him carcasses as he was too young to hunt for himself. Roland Tembo and Ajay Sidhu discovered the nest after rounding up the animals on the Game Trail, and captured the infant for use as bait to attempt to lure the parents into a trap.
The Hunters apparently sedated the animal, and tied him to the ground via a stake. Peter Ludlow stumbled upon the animal while drunk, and seeing what he thought was an animal in the underbrush, fired and stumbled. He landed on the infant T. rex leg, fracturing it, for which Roland was furious about. Ajay and Roland continued to watch the infant from the safety of their tree blind as the animal moaned for his parents.
As the Hunters panicked in the chaos caused by Nick Van Owen and Dr. Sarah Harding freeing the animals, Sarah Harding and Nick took the opportunity to free the infant. Eddie Carr transported the infant from near the Hunter’s campsite to the Mobile Trailers in the Mercedes, despite his confusion and reluctance. They brought the infant onto the trailer, in which they sedated him and set him down on a table at the far end of the second trailer.
As Nick Van Owen and Dr. Harding tried to heal the injured leg of the infant, Kelly Curtis and Dr. Ian Malcolm went to the safety of the high hide along with Eddie Carr. Nick used his belt to muzzle the infant’s jaw to keep him from biting. They used the trailer’s computers to scan the leg, and form a splint so that the leg would have the opportunity to heal from the injury that Ludlow had caused.
However, the cries of the infant had drawn the parents to the site of the trailers, and they signaled their presence by kicking one of the Mercedes off of the cliff. Frightened, Ian, Nick and Sarah attempted to appease the parents by delivering them their infant, now that he was able to walk again thanks to his leg being put in the cast. However, the parents left only for a short while, and when they returned they began to knock the trailers off the cliff in a territorial display.
After the conclusion of the Hunter’s expedition when Roland subdued the male Tyrannosaurus, the surviving members of the expedition went back to the nest and re-captured the infant. The infant was then taken to San Diego via Ludlow’s private jet. where he was placed in the infirmary of Jurassic Park: San Diego. The young male was contained in a small cage that was barely long enough to house his body and no room for him to stand up at all, only for him to lie down.
After the male Tyrannosaurus broke out of his containment in the S.S. Venture and began to rampage around San Diego, Ian Malcolm realized the only way to lure him back to the ship would be by using the infant. Convincing Ludlow to tell them where the infant was held with Sarah’s help, Ian and Sarah drove to the unfinished Park and defied the armed guards to place the infant in the back of their car. Following the screams of the terrified people, Ian and Sarah quickly located where the male Tyrannosaurus was. Sarah woke the infant up, causing him to moan in anguish. The moan drew the male’s attention, and he pursued the car as Ian and Sarah quickly drove back to the S.S. Venture. They quickly placed the infant in the cargo hold and then jumped overboard before the male Tyrannosaurus could follow.
Seeing Ian and Sarah back, Ludlow guessed that they had returned the infant and ventured into the cargo hold where he found him huddled behind a grate. Ludlow thought that he had the infant trapped and so began trying to recapture the animal by himself, although the young male eluded his grasp. He was so fixated on trying to catch the infant that he was completely unaware of the adult Tyrannosaurus coming down the stairs behind him.
Realizing that he had been trapped, Ludlow attempted to run up the stairs. However, the adult grabbed him and threw him roughly onto the ground. It then proceeded to break his legs as he tried to run. The infant began stalking Ludlow, and jumped on him as he screamed. Peter Ludlow was then killed by the infant, becoming the first prey in the infant’s first hunt.
After the adult T. rex was subdued, so was the infant, and the S.S. Venture transported both of the animals to Isla Sorna. This time however, the ship was accompanied by a military escort of ships so as to prevent a repeat of the San Diego Incident. They were then spotted on the plains of Isla Sorna, the entire family group seen out for the first time in their natural ecosystem.