Tyrannosaurus rex ultimus is a fictional subspecies of Tyrannosaurus rex that is featured in the PYTHNUT series. They inhabit the island of Isla Tyrannus.

Role in PYTHNUT Works

T. rex ultimus is the most prominent dinosaur that is featured in the PYTHNUT series, usually being shown in a protagonistic light.

They are depicted as exceptionally dangerous creatures in the series, and have armour covering the entire top of their body to protect themselves from possible danger.

Fact file

Height: 15ft-20ft (4.5-6m)

Length: 62-65ft (18-20m) (Up to 85ft in the earliest strains)

Weight: 15-20 tons (30-40,000 lbs)

Prey: Everything

Predators: Oxalaia rex quimtimus

Bite Force = 50-150 tons / 500,900-1,000,000 newtons

Location: Isla Tyrannus, Dinosaur World

Name means: "The ultimate king of the tyrant reptiles"

Lifespan: Maximum 43 years

Family: Tyrannosauridae

Hunting Style

T. rex ultimus is an apex predator, simply being a more powerful version of the extinct apex predator Tyrannosaurus rex. They retain almost every aspect of hunting strategies from their ancestral T. rex, though, due to living exclusively on small islands, some populations have taken to fishing.


Tyrannosaurus rex ultimus is referred to as the "king" of Isla Tyrannus for a very good reason. They are undeniably the apex predator of the island, only rivalled by Oxalaia quilombensis hadeni and Spinosaurus aegypticus robustus. They are especially infamous for their jaws, which are capable of tearing grown sauropods to shreds. Their arms, though seemlingly weak, are useful as what can only be described as meat hooks; latching onto prey and not letting go until their target has been disposed of.


T. rex ultimus is very large and very heavy, so it can die if it falls off of a short cliff very easily.

Notable T. rex

These are T. rex ultimus with features that differentiate them from others of their kind.


Momma was the among the very first T. rex ultimus to have been born, her begginings in an underground world. All T. rex ultimus are descendants of Momma, but heavily mutated. She was the largest T. rex ultimus to have ever lived, at 40 (12m) feet tall and 80 feet (24m) long. Her weight and age are unknown. Her debut was in Peenut2k7's Jurassic Park V.


Crusher is the chief of the Tyrannolaia Tribe. He was Momma's fourth child, hatched well after the events of the third Ice Age film. He has sustained many injuries in his life, some of the easiest to spot are an Oxalaia bite marks on his neck, Spinosaurus claw slashes on the left side of his upper jaw, and a hole on his belly from a Xenoceratops. His first injury was a wound on his lower jaw made by another T. rex ultimus, and his last known injury was a fatal, skull-crushing kick in the face from a gigantic Angaturama. He is the largest and strongest survivng Tyrannosaurus rex ultimus, at an astonishing 40ft tall (6m), 67ft long (20.5m), 20 tons (40,000 lbs), and a bite force of 150.5 tons. His debut was in Jurassic Park VIII: Power.


Psyclaw, introduced in Peenut2k7's Jurassic Park V, is the father of Momma. He was old for a theropod dinosaur, 54 years, and was extraordinarily large for his species, at 45ft(14m) tall, 82ft(25m) long, 60(100,000lbs) tons heavy. Unfortunately, his hatred for the Spinosaurus species ended up getting him killed in an accident by a sailless Spinosaurus hatchling, Rudy. His remains lie in the Dinosaur World.


T. rex ultimus has an unusual history. In the fall of 1995, InGen's rival company BioSyn sent spies to retrieve the DNA of every dinosaur species on both Isla Nublar and Isla Sorna. The mission was largely a success, though the man behind BioSyn at the time, Jeff Rossiter, demanded they find more DNA for more genuses of dinosaur; though the team had collected the DNA of every species on InGen's two "Dinosaur Islands". Due to the face there were rumors floating around of a new Jurassic Park planned to be open in the very early 21th century, Rossiter instructed the team to wait until there was activity on Isla Nublar.


A Tyrannosaurus putting a Spinosaurus to rest

In the spring of 2003, cloning in (work in progress) Jurassic World was about to begin. While BioSyn sent spies to the WIP Jurassic World. The head scientists got to work on the existing embryos. Later that year, the dinosaurs had been successfuly cloned, and due to a gene that a few of BioSyn's scientists had inserted into them, the hatchlings would be adults by March of the following year; though this gene would end up disappearing once the animals began to breed. In December of 2003, a Spinosaurus broke out of it's exhibit and was killed by a young T. rex. It escaped to Isla Sorna, and eventually, it killed an even bigger Spinosaurus, and bred enough (some of his offspring living in and underground world called Dinosaur World, nowadays) to create an unusual strain of very powerful Tyrannosaurus, these descendants taking very hostile interest in the native, prior genetically altered Spinosaurus subspecies on the island, Spinosaurus aegypticus robustus. The new species was dubbed Tyrannosaurus rex ultimus by BioSyn, who had only recently discovered the new population of super-rexes on Isla Sorna. They grew from 42 feet long to 62+ feet long, and gained enough strength to kill even the most powerful engineered Spinosaurus.

2004 rolled around, and an island in the Gulf of Mexico (dubbed Isla Tyrannus) was chosen as the place to build a knockoff of the upcoming Jurassic World. Unfortunately, this plan was cut short once InGen/Masrani discovered just how BioSyn earned the embryos to make these dinosaurs. This is when it all started. Alan Grant was conned into visiting the island, and thusly had his first run in with BioSyn's weird and wonderful world of mutants. Eventually, the creatures learned of a very similarly powerful creature on the island, a mutant strain of Irritator challengeri dubbed Oxalaia quilombensis hadeni. From then on out, life became a struggle for survival between two species of superpowered dinosaurs. Time would tell what would come of these creatures.


  • Young ones have a chance of being killed by Spinosaurus aegypticus robustus, demonstrated quite brutally in the first book of Jurassic Park V.
  • When hungry or angry, the T. rex is very ruthless, and won't let almost anything it crosses escape. Though when it is not hungry, it will usually let creatures live, though due to its unsurmountably territorial nature, it would almost never let another large carnivore aside from it's own kind live.
  • Tyrannosaurus rex ultimus has an amazing running speed for a large theropod, 24 - 64 mph.
  • It has a septic bite, useful for killing larger prey.
  • The creature's armor goes through evolutionary stages throughout the creature's life. At birth, the Tyrannosaurus has very soft armor. But as the baby gets bigger the armor begins to harden, and once fully grown, the armor is very thick, to the point where only animals with unimagineable strength can snap the armour.
  • It has been known to carry its babies in its mouth, like a mother crocodile or alligator.
  • It could swim like a crocodile, a nod to the Tyrannosaurus in the Jurassic Park novel.


  • It was bigger than a real rex. A real rex was 23ft tall (7m), 39 - 43 ft long (14.5-15.3m), and 8 tons (16,000 lbs).
  • It was stronger than a real rex. A real rex had a bite force of 35,000-57,000 newtons... leading up to a maximum of "only" 12,814 pounds. but even though this is weaker by T. rex ultimus standards, it was the strongest bite on land. Ever.
  • It was much faster than a normal Tyrannosaurus rex, Normal rexes can go, at maximum, 15 miles an hour.
  • It lacked feathers, something which Tyrannosaurus likely sported.
  • How are the islands they inhabit capable of supporting the creature?