"Tyrannosaurus rex (Tyrant Saurian King) is the most famous prehistoric animal on the planet, and is usually what comes to mind when someone hears the word "dinosaur". Tyrannosaurus is among the largest carnivores to ever walk the earth and the apex predator of Hell Creek. It possesses binocular vision, acute hearing and an incredible sense of smell. Although adult T. rex are enormous bulky powerhouses, young tyrannosaurs are extremely lithe in comparison, with thin snouts and long ostrich-like legs used for pursuing fast prey."

Saurian encyclopedia

Tyrannosaurus, also known as T. rex, was a large carnivorous theropod dinosaur that lived from 68 to 66 million years ago in the late Cretaceous. Tyrannosaurus is one of the most well known and most iconic prehistoric animal that has ever lived. It will be one of the playable dinosaurs in the base Saurian game.[1]


Tyrannosaurus rex measures around 12 meters (40 feet) long, with particularly large specimens approaching 13 meters (43 feet), stands approximately 3.7 meters (13 feet) tall at the hips, and weighed at least 7-8 tons. It was the largest terrestrial carnivore ever discovered in North America.

Tyrannosaurus were both hunters and scavengers like many modern predators, hunting hadrosaurs (such as Anatosaurus), ceratopsians (such as Triceratops) and even the occasional ankylosaur (such as Denversaurus and Ankylosaurus). Tyrannosaurus had one of the most powerful bite forces of any terrestrial animal ever to live, with a bite force surpassing many modern animals. Scientists presume that the bite force of Tyrannosaurus was 12,000 to 12,800 pounds (53,378 to 56,937 newtons) per square inch. Philip J. Currie of the University of Alberta has suggested that Tyrannosaurus may have been a pack animal. A study from Currie, Horner, Erickson and Longrich in 2010 has been put forward as evidence of cannibalism in the genus Tyrannosaurus. They studied some Tyrannosaurus specimens with tooth marks in the bones, attributable to the same genus.

There is debate on whether Tyrannosaurus had plumage or not. Its cousins Dilong and Yutyrannus had been discovered with feathers, and may have been present in other Tyrannosauroids as well. To most paleontologists, it seems very likely that Tyrannosaurus had at least some feathers. However, recent analysis on tyrannosaurid skin impressions, show that probably Tyrannosaurus lacked a dense coating of feathers and, if it had feathers, it will be in a similar way to how an elephant's fur is spread across its body. Dense feather coatings would most likely have been found on the torso, if they existed. The studies that propose a significant lack of feathers on Tyrannosaurus are based on the discovery of small skin impressions found in many members of the Tyrannosauridae that show scales on many parts of the body. Although this may indicate a significant lack of feathers, the study doesn't take in consideration that feathers can grow alongside scales in some dinosaurs, like in Juravenator.

A study in 2016 suggests that large theropods, like Tyrannosaurus, had enamel on it's teeth, which would mean they had their teeth covered in saliva, and therefore they would have to be protected from the exterior. It has therefore been suggested that Tyrannosaurus had lips covering it's teeth. This is, however, controversial, since in 2017, the comparison between the bone texture of Daspletosaurus and crocodilians, suggests that tyrannosaurs had large, flat scales on their mouths. This seems that, beyond indications of the existence of sensory neurons, between these scales, that were possibly used for identification of objects and measurement of temperature in the nest, tyrannosaurs would probably be lipless. Although the 2017 study doesn't discuss the possibility of lips existence in tyrannosaurs, most scientists consider this as evidence that tyrannosaurs, possibly including Tyrannosaurus, potentially did not had lips. However, the bundles that exist in the skulls of tyrannosaurs resemble more those of komodo dragons than those of crocodiles, indicating that tyrannosaurids may have had komodo dragon lips, instead of crocodilian lips.

Physical appearanceEdit

Current appearance Edit

The Tyrannosaurus has a mix of feathers, scales, and bare skin. Initially, the Tyrannosaurus spends most of its life as a slim theropod, but when it matures into an adult it gains more bulk, as shown in the animals growth curve. Tyrannosaurus colors range from brown, white, and gray to match with its habitat, with its feathers growing progressively darker as it ages from hatchling to adult.

Future appearance Edit

Tyrannosaurus is completely scaly throughout it’s life. It spends it’s early life as a colorful, slim theropod. As it matures, it’s scales grow progressively darker to better match it’s habitat, save for it’s "eyebrows" and stripes on the neck. Tyrannosaurus' colors range from a dark brown (back), tan (underbelly and dorso), cream (transitional stripes on the dorso) and orange (ridges above the eye). This may change over time, as the new model is still in development.

Behavior and BiologyEdit

Rjpalmer trex ontogeny 005

Concept art of the life cycle of Tyrannosaurus.

Tyrannosaurus is the apex predator of the Hell Creek. A hyper-carnivore, it will eat most animals as an adult, but prefers the slow moving Anatosaurus and Triceratops as prey, targeting young and weak individuals as most smaller prey are too fast and nimble. Adult Tyrannosaurus will occupy large territories to sustain their requirements for food, defending their territories diligently. When two adults meet outside of breeding season, the results are usually violent, with face biting being common in these conflicts.[1]
Trex infographic


During breeding season, males and females locate each other and emit low-frequency sounds during courtship. After mating, the female Tyrannosaurus leaves the male, leaving the him to watch after the eggs and young. Tyrannosaurus displays strong parental care by watching over broods for years until their young reaches a moderate size. When this occurs, the father finally departs, but the juveniles stay together in a sibling pack, hunting prey together until they reach adulthood. Unlike the adults, younger Tyrannosaurus are extraordinarily fast. Young Tyrannosaurus use this trait to their advantage in hunting prey such as the Hell Creek Ornithomimid and Anzu.[1]

At some point in its life, or possibly all its life, Tyrannosaurus will exhibit cannibalism.[2]

In Saurian Edit


Hatchling Dakotaraptor in the sight of a Tyrannosaurus

Tyrannosaurus is planned to be a playable animal in the future, but currently it is only an AI, and serves as a predator for any Dakotaraptor player. Hatchling and juvenile players are too small for the Tyrannosaurus to have any immediate interest, and some players use this as a means to follow one and take the meat that is taken down by one. However, getting anywhere close to a Tyrannosaurus at a more advanced life stage is risky for the player, as the former will see them as prey. Tyrannosaurus can kill the player with just one bite. The player cannot practice RPR on a Tyrannosaurus, currently, and so it is nearly impossible to take one down, as the player will most likely succumb to its quick reflexes. Despite being almost impossible to be brought down, however, there's a tactic, used by some players, to kill one: bite it once, lure it to a herd of Triceratops, and all the player has to do next is to wait until the Tyrannosaurus flees injured, or is finished by the herd.

Currently there is no sexual dimorphism or ontogenic variety in Tyrannosaurus.

Behind the scenesEdit


Original Tyrannosaurus design by Alex "Doc" Lewko from 2013.

All members of Saurian's concept artists were involved in designed the Tyrannosaurus.[3]

Based on the specimen FMNH PR 2081 "Sue"[4] (particularly a now inaccurate skeletal by Scott Hartman)[5] and designed by Alex "Doc" Lewko, the pre-2015 design of the Tyrannosaurus was different than the current design. It had black feathers spanning from the top of its head down to the tip of its tail. The feathers on the top of the head and under the throat were not as thick as the rest of the body. The head markings on the original concept were orange with a white horizontal stripe starting mid-head through the neck being split by the theropod's eye. Another version also by Lewko featuring the face being dark blue with red wattle and lighter orange marking mixed with pink markings. The white stripe that ran mid-head down to the neck was also absent. The latter design was made into a model, being originally utilized for the video game Project Crynosaurs,[6] which the Saurian developers were originally apart of[7] until they split and created Saurian.[8] Upon the split, the Tyrannosaurus model saw usage in early stages of the game's development.[9]

T. rex improved feathers

Original Tyrannosaurus model.

In 2015, the Tyrannosaurus received a redesign. This redesign was spurred by a variety of factors. One of these factors was that RJ "Arvalis" Palmer had been frequently requesting the development team for a redesign due to a number of issues the then current design had. Jake Baardse's improved skills and more knowledge of the anatomy of Tyrannosaurus also played a role in redesigning the game's Tyrannosaurus, but it was the conversion from the CryEngine to the Unity game engine that played a prominent role in the dinosaur's new look. The original model created for the CryEngine from 2013 was old and despite it working in Unity, the steps taken to make it work in CryEngine limited the team's animator Bryan Phillps ability to set up ragdolls as well as other basic functions. Furthermore, new techniques that Phillps had an interest in implementing were stymied by the old model. The CryEngine model also caused problems for the team when they were updating and correcting discrepancies per newfound information.[5]


Unused design of the Tyrannosaurus by RJ "Arvalis" Palmer.

All of the concept artists for the game were involved in the redesign.[3] RJ Palmer created many potential designs for the new Tyrannosaurus.[10] One design had a black coat of feathers covering the upper torso with small, stringy plumage on the back of its neck and at the tip of the tail. Its head was completely void of feathers.
Saurian tyrannosaurus rex by arvalis-d970uqo

Redesigned Tyrannosaurus rex concept art by RJ Palmer.

The redesign featured feathers spanning from the top of the head, covering the majority of the torso, to the top of the base of the tail. The feathers themselves were brown and tan with a new non-frayed design, presumably from the game's researcher Tom Parker's research into dinosaur integument. The feet were redesigned based on fossil tyrannosaur track-ways discovered in Canada in 2014. The specimen "Stan" was chosen in place of "Sue" to design the new Tyrannosaurus. In the blog post unveiling the game's new look for the Tyrannosaurus, Nick Turinetti explained that this was because of Stan's smaller size, but it was more primarily due to the fact that Stan lived closer to Saurian's setting than Sue which would allow for more accuracy.[5] The new design would further receive changes when its model was made, particularly a more elongated skull and a thinner lower jaw.

The "new design" of Tyrannosaurus by RJ Palmer as an April Fool's joke.

In addition, the specimens MOR 6625 "Chomper" and BMRP 2002.4.1 "Jane" served as references for the juvenile and sub-adult Tyrannosaurus respectively.[11] The specimen "Jane" is debated among paleontologists on whether or not it is actually Tyrannosaurus or Nanotyrannus.

For April Fool's 2015, RJ Palmer created a "new design" for the Tyrannosaurus that was purposely inaccurate, standing on its tail among other inaccuracies.[12]

In 2017 new studies provided sufficient information for a redesign on the model. This new model is mostly, if not all scaly and has no visual feathers.




For a more complete gallery, visit Tyrannosaurus/Gallery

Notes and referecnesEdit

  1. 1.0 1.1 1.2 Playable Animals. Saurian Website. Retrieved September 7, 2016
  2. Excrepted from Part 2 of the September 19, 2016 livestream at 00:21:11:
    hitchcockzoo : @SaurianGame, Will the T. rexes be cannibals?
    SaurianGame\s : yes
  3. 3.0 3.1 Sabriana. (September 9, 2015) I Know Dino Podcast Show Notes: Acheroraptor (Episode 43). Retrieved September 9, 2016
  4. Switek, Brian. (December 14, 2014) Behind the Scenes of ‘Saurian’, a Dinosaur Simulator. Dinologue. Retrieved September 7, 2016.
  5. 5.0 5.1 5.2 Turinetti, Nick. (September 7, 2015) Redesigning a Tyrant: Meet the New Tyrannosaurus rex. Saurian Website. Retrieved September 7, 2016.
  6. CRYENGINE - Project Crynosaurs - The Ambush. YouTube.
  7. (September 2013) Interview: Project Crynosaurs. Cunzy1 1's Dinosaurs in Games Blog.
  8. (November 3, 2013) Saurian Facebook.
  9. Saurian: Hell Creek Pre-Alpha Gameplay. YouTube
  10. Saurian-Tyrannosaurus rex. Deviantart.
  11. Turinetti, Nick. (April 17, 2016) April 13th Livestream: The Aftermath. Saurian Website. Retrieved September 7, 2016.
  12. (April 1, 2015) Saurian Facebook.
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