Teratophoneus curriei (S/F)

Adult and juvenile Teratophoneus reconstructions at the Natural History Museum of Utah

Teratophoneus (genus name meaning “monstrous murderer”) was a medium-sized genus of tyrannosaurid dinosaur that lived during the Campanian age of the Late Cretaceous period, from 77 to 76 million years ago. It inhabited what is now North America, with fossils being found in the Kaiparowits Formation of southern Utah. At the time, this was a coastal environment of the subcontinent Laramidia. The specific name honors Canadian paleontologist Philip J. Currie, an expert on species found in the Dinosaur Park Formation including tyrannosaurid relatives of Teratophoneus. This genus is considered a more primitive member of the tyrannosaurines, the subfamily that includes Tyrannosaurus rex.

Fossil remains of a subadult were first discovered in 2011 by paleontologists Thomas D. Carr, Thomas E. Williamson, Brooks B. Britt, and Ken Stadtman. The remains included an incomplete skull, along with scattered remains of the rest of the body; originally, paleontologists assumed that the remains were from four different Teratophoneus. Modern scientists believe that the remains all belong to the same individual. In 2013, it was classified as a basal tyrannosaurine. Fossils of this genus are rare, with only a handful of specimens having been discovered. Three are exhibited in public museums, while a possible fourth was owned by Benjamin Lockwood and kept at his family estate. So far, only this one species has been identified in its genus.

At some point before December 2015, International Genetic Technologies succeeded in cloning this tyrannosaur from ancient DNA recovered from mosquitoes trapped in Campanian amber samples. No specimens have been seen alive in recent times, leading to speculation that this animal may have fallen into extinction.


This was one of the smaller tyrannosaurs. Fossil remains suggest that it grew to around 21 feet (6.4 meters) in length and weight 1.15 tons (1,043.3 kilograms). The skull was shorter and deeper than those of other tyrannosaurs such as Albertosaurus, possibly allowing for stronger jaw muscles giving this species a more powerful bite. Its teeth were long, slightly curved, and serrated in characteristic tyrannosaurine fashion, with larger teeth situated in the middle of the jaw while the teeth in the front and rear were smaller. These would have been replaced regularly throughout the animal’s life. Its eye orbits featured small ridges, not as dramatic as in related animals. Its eye anatomy is currently unknown as no live specimens have been observed, but the more derived Tyrannosaurus rex has yellow sclerae and round, birdlike pupils. The tongue of Teratophoneus is long and muscular, appearing to have been more flexible in InGen specimens than in their ancient ancestors. This is also the case in Tyrannosaurus.

Other features of Teratophoneus were similar to its relatives as well, with its size and skull anatomy being the main diagnostic characteristics. Its neck was not exceedingly long, but strong in order to support its skull; it had a mostly rigid tail for counterbalancing purposes and birdlike hips. The legs were lengthy and powerful, with three-toed feet each ending in a curved talon. A fourth toe, the dewclaw, was vestigial and did not reach the ground. The maximum speed of Teratophoneus is unknown, but its larger relatives may reach speeds of up to 32 miles per hour for short bursts. Its arms, as with all tyrannosaurs, were reduced in size with only two visible fingers, each bearing a small curved claw. Like with most of InGen’s dinosaurs, these hands are capable of pronating, turning so that the palms face downward, which the original creatures could not do.

Most tyrannosaurs have excellent senses of smell, sight, and hearing, and Teratophoneus was likely no exception.

The skin color for this creature is not known, since the only specimen observed so far was a desiccated carcass. Skin on the carcass was light gray in color with some hints of darker striped or splotched patterning, with dark skin around the eyes. The tongue was dark gray. Since the carcass had been out in the elements for some time when it was found, its original colors may have faded due to blanching and dehydration. The skin on the carcass had begun to shrivel, but its scaly surface was still defined; the animal may have possessed feathers in prehistory, but most of InGen’s genetically-modified animals lack these due to a historical splicing error. Since Teratophoneus was cloned more recently, it may have possessed some feather quills somewhere on its body which fell off after its death. Alternatively, this animal may have been secondarily featherless in prehistory as well; most theropods, including modern birds, have at least some scales on their bodies along with feathers. In birds, the feet are scaly, while some prehistoric theropods had scaly skin on other regions of the body.

The colors of this animal may be implied in the pre-production rendering of a currently unidentified tyrannosaur that would have appeared in 2018. It appears physically similar to Teratophoneus but has not been named. This tyrannosaur has a yellow-green body with darker mottling on its back and whitish countershading on the belly and legs. Its head, like its back, is darker green in color, and the supraorbital crests are bright red.


In the related Tyrannosaurus, juveniles hatch with colors similar to the adult females but with proportionately larger heads and narrower teeth. Teratophoneus most likely had similar ontogeny, showing these same changes as it grew. Its lifespan and growth rate are unknown; InGen frequently sped up the growth of its animals through genetic manipulation and hormone supplements, so it is likely that cloned Teratophoneus reached maturity at a faster rate than normal.

Sexual Dimorphism

It is possible and likely that Teratophoneus showed similar sexual dimorphism to the better-studied and larger Tyrannosaurus. In that species, males show a darker and more vibrant coloration as well as keratinous growth on the snout giving it a more rugged appearance. Males engage in intraspecific combat for mating rights, so they often show scarring on the snout where other males have bitten or clawed them; they may also be seen with missing or broken teeth from hunts or combat. Female T. rex, however, have a larger maximum size, though not all of them get this big.

Preferred Habitat

In prehistory, Teratophoneus inhabited coastal floodplains including environments such as rivers, ponds, estuaries, peat bogs, salt marshes, and forests. Highlands are known to have been nearby, but so far no fossils have indicated a preference for mountainous environments. Prey animals were abundant in its habitat. Following its de-extinction, Teratophoneus appears to have favored the boundaries of forests, much like its larger relative Tyrannosaurus. A carcass was found from an animal that was killed in territorial combat next to a building, suggesting that they may have used landmarks to define their territories.

Isla Nublar

Sometime before December 2015, Teratophoneus was cloned by International Genetic Technologies geneticists under Dr. Henry Wu on Isla Nublar. There is no evidence that it was ever exhibited at Jurassic World, and instead was probably maintained in a controlled habitat in the island’s north away from tourists. It is also missing from a list of animals compiled by the Dinosaur Protection Group, which (along with its absence in the park) suggests it was a recent creation by 2015. At least one was created, but population statistics are not known.

On December 22, 2015, Jurassic World experienced a major security incident which led to the park closing indefinitely. The island was abandoned, and animals were able to roam freely. Teratophoneus now had access to the island’s variety of habitats and food sources. At least one specimen survived until maturity. It died in territorial combat sometime in the weeks preceding June 23, 2018. Its carcass was found next to Radio Bunker 02-17 just southeast of Mount Sibo. No living specimens were seen on the island at that time. If any did survive, and were not removed from the island, they probably became extinct in a volcanic eruption occurring on June 23.

Isla Sorna

Teratophoneus is not known from Isla Sorna. Since no cloning activities have been confirmed to happen on that island since mid-1999, it is most likely that this species never lived there.


While Teratophoneus appears to have been a rare animal, it is still possible that it was affected by poaching between its creation and the 2018 eruption of Mount Sibo. However, no specimens have been confirmed off Isla Nublar, suggesting that it may be extinct.

Behavior and Ecology
Daily Activity

The activity patterns of Teratophoneus are not currently known. Other tyrannosaur species are cathermal, but favor diurnal activity.

Diet and Feeding Behavior

Teratophoneus was a carnivorous animal and killed prey using its powerfully-muscled jaws and serrated teeth. Like other tyrannosaurs, it probably had excellent senses of smell and hearing that would have helped it track prey. Carnivorous animals will scavenge carcasses when they have the opportunity, and with the ecosystem of Isla Nublar collapsing between 2015 and 2018, the island’s Teratophoneus would have had ample opportunity to do so.

Because of its smaller size compared to some theropods, Teratophoneus probably could not have targeted all of the herbivorous dinosaurs in its environment. Instead, it most likely fed upon smaller and less armored prey. It appears to have lived at the edges of forests, which would have provided it cover from which to ambush prey, but its strong legs would have allowed it to chase down food items as well.

Social Behavior

It is unknown how many Teratophoneus, if there were more than one, were bred on Isla Nublar. Larger tyrannosaurs show mostly solitary behavior in the wild, but in captivity, subadults have been acclimated to the presence of others of their kind. The smaller Teratophoneus may have shown similar behaviors.


All dinosaurs lay eggs to reproduce, and the eggs of theropods such as Teratophoneus are ovoid in shape to prevent them from rolling away from where they are placed. The better-researched Tyrannosaurus forms monogamous mated pairs, with males engaging in combat for mating rights. Mating is accomplished using the cloacae, reproductive organs that are seen in present-day birds. Eggs of medium-sized species such as Teratophoneus usually incubate for a period of three to six months.

Teratophoneus carcass near Radio Bunker 02-17, Isla Nublar (6/23/2018)

It is most likely that Teratophoneus has similar reproductive behaviors to other tyrannosaurs. Their nesting and rearing patterns are somewhat similar to modern crocodilians. In T. rex, both the male and female guard the nest and provide for their offspring, capturing prey animals and stockpiling carcasses at the nest. The juveniles are eventually taught how to hunt using injured live prey.

Maturity in tyrannosaur specimens affected by InGen’s growth-boosting methods can be reached in as little as five years. Sexual maturity is reached about as quickly, with powerful parenting instincts having already developed by this time.


While the vocalizations and body language used by Tyrannosaurus rex are well-understood and documented in abundance, no living Teratophoneus have been observed yet. Therefore, it can only be assumed that they use similar techniques to communicate with one another.

Ecological Interactions

In prehistory, Teratophoneus was a top predator in a coastal environment that included an abundance of herbivorous species. Some of the genera it once lived alongside, including Parasaurolophus and Nasutoceratops, were cloned on Isla Nublar. Once in the wild, it would have been able to encounter dozens of other animal species; among the de-extinct wildlife found in its habitat were armored herbivores Triceratops, SinoceratopsPachyrhinosaurusStegosaurus, Peloroplities, and Ankylosaurus, sauropods Apatosaurus and Brachiosaurus, the fleet-footed Gallimimus and Stygimoloch, and the tiny scavenger Compsognathus. It likely preyed upon the smaller species, and juveniles of the larger ones. Competition for food and territory came from new carnivorous species it would have encountered: its environment included similarly-sized predators such as Carnotaurus, Allosaurus, Pteranodon, and Baryonyx, as well as the far larger Tyrannosaurus.

The only known specimen of Teratophoneus was found having died of an apparent territorial clash. Its cause of death appears to have been internal separation of the cervical vertebrae and severing of the spinal cord, caused when its skull was twisted at least one hundred eighty degrees with respect to its shoulders. Large, three-fingered claw marks could be seen on its neck. These attack patterns are similar to those known from Spinosaurus aegyptiacus, though a smaller spinosaurid may have been the animal responsible.

The Teratophoneus was also affected by parasites, such as hematophagous insects and other invertebrates. Mosquitoes and other creatures drank its blood to fuel egg development, which was probably how InGen obtained Teratophoneus DNA. It is unknown how modern parasites affected it.

Relationship to Humans

At some point around 2015, InGen’s geneticists cloned Teratophoneus currieri, housing it at the facilities on Isla Nublar, Costa Rica. It may have been intended for eventual exhibition in Jurassic World, but it was not yet ready for life in the park.

Teratophoneus skeleton in the Lockwood estate

This animal’s recent creation and relative obscurity means that it was not well-known even to Jurassic World’s own staff. The park’s former Senior Assets Manager, Claire Dearing, neglected to include it on a list of Isla Nublar’s species for the Dinosaur Protection Group. As a result, it got no attention from animal rights activists between 2017 and 2018, when Isla Nublar’s ecosystem was threatened by volcanic activity.

A full-body reconstruction of Teratophoneus was on display in the private museum at the Lockwood estate, owned by InGen founding father Benjamin Lockwood. While this appears to have been a fossil, it may also have been a skeleton from a Jurassic World specimen, since Teratophoneus fossils are exceedingly rare.

Behind the Scenes
Finishing touches are put on the model behind the scenes.

This animal was planned to appear as a decaying carcass just outside the radio bunker in Jurassic World: Fallen Kingdom, but in the final film, most of the footage that included dinosaur carcasses was cut for unknown reasons at the last minute. A single shot of the Teratophoneus carcass is still visible in the film. This species also appeared as a prop in the Lockwood estate, with a model based on real T. currieri fossils found in the Kaiparowits Formation.

Deleted scenes imply that some form of small tyrannosaur was planned for the first act’s climactic stampede scene. One such scene made it as far as the CGI phase, but while this was originally assumed to feature a Teratophoneus hunting a juvenile Triceratops before being killed by an adult, it has since been determined that this was meant to be an Allosaurus. Another pre-production rendering of the stampede scene does actually show an unidentified tyrannosaurid, speculated to be Teratophoneus, but this was ultimately replaced with Allosaurus in the final film.

The carcass of the Teratophoneus shows damage consistent with a Spinosaurus attack, which would have foreshadowed the appearance of a Spinosaurus in the film, but this animal was also cut from the final version.