Deinosuchus rugosus (S/F)

Deinosuchus rugosus was a very large species of alligatoroid native to North America during the Campanian epoch of the late Cretaceous period, from 82 to 73 million years ago. Its teeth were first discovered in 1858 by geologist Ebenezer Emmons (who assumed it to be a pliosaur), and its genus was named by W.J. Holland in 1909 following the 1904 discovery of osteoderms belonging to it. More remains were discovered in the 1940s, bolstering knowledge of the animal. While not a direct ancestor of the modern alligator, Deinosuchus had a number of morphological traits in common with them, and greatly resembled a larger version of the alligator. At the time it existed, North America was divided into two subcontinents by a warm sea known as the Western Interior Seaway. In the east was the subcontinent of Appalachia, while in the west was the subcontinent of Laramidia. Fossils of Deinosuchus have been found on ancient coastlines of both, and it is presumed to have been an apex predator. The scientific name means “rough, terrible crocodile,” in reference to its osteoderms and imposing size. The name is somewhat misleading, as it is more closely related to alligators than to crocodiles.

Some scientists consider Deinosuchus rugosus to be a dubious species, claiming that the remains from its habitat have not been properly described. This species is one of at least two and at most three known species of Deinosuchus; it grew to roughly 26 feet long, inhabiting the Appalachian subcontinent. Laramidia was home to the larger Deinosuchus hatcheri, and the similarly large Deinosuchus riograndensis lived farther south. These latter two may represent a single species, and reached a maximum size of 32 to 39 feet in length. However, despite its huge size, Deinosuchus was not the largest crocodilian ever to live. The North African Sarcosuchus, Indian Rhamphosuchus, and South American Purussaurus all grew to equal or larger size.

InGen utilized Deinosuchus rugosus genetic material in engineering the artificial species Indominus rex, which hatched in 2012. There is scant evidence that InGen recreated D. rugosus itself.


Deinosuchus mostly resembles the modern-day American alligator (Alligator mississippiensis), but is significantly larger in size. The species D. rugosus in particular reaches lengths of 26 feet. This makes it larger than any living crocodilian, including the saltwater crocodile (Crocodylus porusus), though not larger than several genera of crocodilian which existed later in time than Deinosuchus. Like its modern relatives, it was a bulky quadruped with lengthy jaws ending in a round, U-shaped snout with nostrils on the top. Its teeth were thick and robust, with the teeth toward the snout being sharper and designed for puncturing flesh while the teeth in the rear of the mouth were blunter and rounded for crushing armor and shells. Each premaxilla had four teeth, each maxilla had twenty-one or twenty-two teeth, and the dentaries of the lower jaw had at least twenty-two teeth each. When the jaw was closed, only the fourth tooth of the lower jaw would protrude. This animal is estimated to have had a bite force of 18,000 to 102,803 Newtons. If the higher estimates are correct, then its bite force would exceed even that of Tyrannosaurus rex.

Holographic display of Indominus rex, indicating that Deinosuchus rugosus was used to design its dentition.

Also like modern crocodilians, the body of Deinosuchus is covered in bony osteoderms, which function both as armor and as attachment points for connective tissue. Deep pits and grooves in the osteoderms worked to connect with this tissue. In combination, these osteoderms and connective tissue would work as a load-bearing system to support the bulk of the animal when it was out of the water. The osteoderms were larger than average, and many were shaped like hemispheres.

Deinosuchus is believed to have had a lengthy tail constituting almost half its total length. This tail would have probably been highly muscular for propulsion when swimming. The limbs would likely have been small, but also muscular, with little use in swimming but necessary for dragging its heavy body over land.

Its coloration is currently unknown, but it has been depicted with a light brown or tan color in Jurassic Park: Builder.


Hatchling and juvenile stages have not been observed. Most modern crocodilians somewhat resemble adults when they hatch, though with disproportionately larger heads and eyes, and sometimes brighter coloration. The mobile game Jurassic Park: Builder depicts young Deinosuchus as smaller versions of the adults.

Fossil evidence suggests that Deinosuchus reached adulthood in about 35 years, and may have had a lifespan of more than 50 years.

Sexual Dimorphism

So far, no sexual dimorphism in Deinosuchus has been documented.

Preferred Habitat

Deinosuchus is presumed to have inhabited estuarine environments and brackish-water bays. As with all similar crocodilians, it would have been semiaquatic, being an excellent swimmer but still capable of walking on land. In particular, D. rugosus inhabited Appalachia, a subcontinent of North America that existed during the Campanian. Fossils are known from the tropical coasts of the Western Interior Seaway, as well as the Atlantic coast of the subcontinent. It is unknown if Deinosuchus could tolerate saltwater or if it ever ventured out to sea.

The mobile game Jurassic Park: Builder incorrectly portrays Deinosuchus as living comfortably on the frozen Patagonian coast, near El Chaltén within Los Glaciares National Park. In reality, an ectothermic crocodilian could not survive in this kind of environment.

Isla Nublar
Deleted footage featuring what may be a Deinosuchus skeleton. The size indicates that it would be a subadult, if it is indeed a Deinosuchus and not some other variety of alligatoroid.

While Deinosuchus DNA was utilized to design the tooth morphology of Indominus rex, it is not known if any were actually created by InGen. The only evidence of its existence is a single skeleton seen to the southwest of Mount Sibo on June 23, 2018; the skeleton appears to belong to a large alligatoroid similar to Deinosuchus, but its identity is unconfirmed. Deinosuchus is absent from a list of de-extinct life on Isla Nublar created by the Dinosaur Protection Group; if it was indeed cloned, then either Jurassic World administration was unaware of it (similarly to Troodon), or the DPG’s members simply neglected to include it in the list. It is not the only species missing from the list for unknown reasons, as both Teratophoneus and Peloroplites are similarly absent despite confirmation of their existence on Isla Nublar.

The skeleton was found in a heavily-forested region in a small creek. If any survived until 2018, it is likely that the June 23 eruption of Mount Sibo would have wiped out their food sources and, consequently, any surviving Deinosuchus.

Isla Sorna

There is no evidence that Deinosuchus was ever present on Isla Sorna.


As it is not known whether Deinosuchus was actually created at any point (or, if so, if any survived), there is no evidence for it being brought to the mainland in any form.

Behavior and Ecology
Daily Activity

As an ectothermic (cold-blooded) reptile, Deinosuchus would most likely be diurnal or cathermal, resting during the night.

Diet and Feeding Behavior

The estuarine habitat of Deinosuchus would enable it to hunt both terrestrial animals, such as dinosaurs and pterosaurs, as well as aquatic animals such as fish. Its teeth were adapted for multiple uses, with the front ones designed to puncture flesh while the rear ones were designed to crush shells and bony armor. It could have theoretically fed on shellfish and armored animals such as turtles. There is some debatable fossil evidence of Deinosuchus hunting hadrosaurs, and certainly its large size would enable it to prey on some of the dinosaurs it lived alongside.

Many modern crocodilians will ambush prey at the water’s edge, then submerging the prey until it drowns. Fossil evidence and biomechanical studies suggest that Deinosuchus could perform a death-roll like some modern crocodilians, killing captured prey by internal injury.

As no living specimens have been documented so far, it is not known what the prey of de-extinct Deinosuchus would include. However, some larger animals known from its possible locality on Isla Nublar include Stegosaurus, Sinoceratops, and Peloroplities.

Social Behavior

No evidence currently exists to provide any information on the social behavior of Deinosuchus, though many modern crocodilians are comfortable living in large groups.


Nearly all crocodilians lay eggs to reproduce, the only possible exceptions being certain fully-marine lineages. As of such, the Deinosuchus almost certainly laid eggs. Crocodilians utilize cloacae as reproductive organs, though the male possesses a median penis. The sex of the offspring is determined by temperature; moderate temperatures result in males, while temperature extremes result in females. Most modern crocodilians, including close relatives of Deinosuchus, engage in complex courtship rituals, extensive nest-building, and extended parental care given by the mother; it is possible that Deinosuchus also exhibited these behaviors.

The extant American alligator, which is closely related to Deinosuchus, lays 35 to 90 eggs and incubates them in a nest for about sixty-five days. As Deinosuchus is much larger in size, its clutch size and incubation period may have differed from the American alligator.


The exact vocalizations of Deinosuchus are not known. Modern alligators are able to produce hissing sounds when threatened, and some (particularly males) will forcefully exhale to make a loud throaty bellowing noise. This may be used as a display call, advertising to mates and threatening rivals. Crocodilians lack vocal organs, so their vocalizations are limited. They mostly communicate through body language.

Ecological Interactions

Deinosuchus rugosus was smaller than its relative Deinosuchus hatcheri, so while its larger relative was probably an apex predator, D. rugosus was more likely an opportunist. If it existed on Isla Nublar, it would have had competition with many genera of large carnivorous dinosaur, including Tyrannosaurus and the semiaquatic Baryonyx and Suchomimus. A single skeleton possibly belonging to D. rugosus was featured in deleted footage, implying that (if the skeleton was indeed from this species) it was at least found near Mount Sibo’s heavily-forested southwestern slopes. A creek was present at that location, though it was not deep enough for the animal to submerge.

Within the region of island where the skeleton was found, known species of dinosaur included the armored herbivores Peloroplities and Stegosaurus, ceratopsian Sinoceratops, the diminutive carnivore Compsognathus, large pterosaur Pteranodon, and a single Velociraptor.

At least in prehistory, Deinosuchus was affected by hematophagous (blood-drinking) parasites, possibly mosquitoes.

It is possible that the species had already died out by June 23, 2018 when the skeleton was found, likely due to competition from the excessive number of predators on Isla Nublar after the island was abandoned by Masrani Global Corporation.

Relationship to Humans

Thus far, no human interactions with Deinosuchus have been reported. It was sourced as a component for the genome of Indominus rex, particularly its tooth morphology.

Crocodilians are among the natural predators of humans, so it is possible that a large species of crocodilian such as this one may view humans as prey.

Behind the Scenes

A piece of concept art for Jurassic World depicts an attraction where visitors would view large reptiles that appear to be crocodilian in nature. The visitors would walk on glass panels above the reptiles to view them. It is not known if these were intended to be Deinosuchus, or if any such attraction was ever considered for the theme park in-universe.