Ankylosaurus magniventris (S/F)

Ankylosaurus is a genus of very large thyreophoran dinosaur in the family Ankylosauridae, which gets its name from this genus. It first lived during the Maastrichtian epoch of the late Cretaceous period between 68 and 66 million years ago, inhabiting what is now western North America. Its genus name means “fused reptile,” referring to the state of its bones, which were fused together to give it additional protection from predators. It can also be translated as “curved reptile” or “stiff reptile,” also referring to its skeletal structure. Only one species is known, A. magniventris; this species name means “great belly” in reference to this dinosaur’s portly appearance. This was one of the last armored dinosaurs to evolve, and is currently the largest species of its kind to be discovered. Ankylosaurus material has been found in the Hell Creek Formation (Montana, USA), Lance and Ferris Formations (Wyoming, USA), Frenchman Formation (Saskatchewan, Canada), and Scollard Formation (Alberta, Canada).

Fossilized remains of this animal are fairly rare. The first was a fairly complete skeleton discovered in the Hell Creek Formation of Montana in 1906, found by collector Peter Kaisen with an expedition from the American Museum of Natural History led by paleontologist Barnum Brown. The skeleton included the upper part of a skull, two teeth, part of a shoulder, numerous vertebrae, ribs, and more than thirty osteoderms. Two years later in 1908, Brown scientifically described the skeleton as Ankylosaurus magniventris, reconstructing the missing parts based on the similar Stegosaurus.

Mature Ankylosaurus in running position. It can move fast when pressed to do so, but is generally a slow-moving creature.

Brown would lead another expedition in 1910 to the Scollard Formation in Alberta, Canada where he would discover another set of Ankylosaurus remains, this time including the tail. This fossil revealed that the dinosaur’s tail ended in a stunningly thick club structure, which could presumably be used to defend the animal from attacks from the rear. Paleontologists have suggested that this club originally evolved for intraspecific combat, for example two male ankylosaurs fighting for mating rights.

In total, five incomplete skeletons of Ankylosaurus have been found, as well as many osteoderms which must have broken away from skeletons. Although this dinosaur is certainly the most famous of all the ankylosaurs, it is actually quite unusual when compared to its relatives, differing in skeletal structure in a number of ways. Reconstructions in the past have often referenced other types of ankylosaurs when depicting Ankylosaurus, resulting in models with inaccurate or speculative features.

During the 1980s and 1990s, International Genetic Technologies sourced amber samples from North America which yielded Ankylosaurus DNA obtained from inclusions. Using these gene samples, they were able to reconstruct up to 91% of the Ankylosaurus genome by 1993, but there is currently no evidence that any were cloned by that time. The first confirmed case of Ankylosaurus cloning was performed illegally by InGen under Masrani Global Corporation in late 1998 or early-to-mid-1999, when de-extinction was explicitly outlawed by the Gene Guard Act.


The largest-known of the ankylosaurs, Ankylosaurus measure 18 to 32.8 feet (5.4 to 9.99 meters) in length and 4.6 to 5.6 feet (1.4 to 1.7 meters) high at the hips. To the top of the back, rather than the hips, it measures six to nine feet (1.83 to 2.74 meters) tall, with some reaching 11.8 feet (3.6 meters). Adults can weigh between 7,998 and 17,600 pounds (3,628 and 7,983 kilograms).

The boxy triangular head of this dinosaur is also proportionally large, measuring 2.12 feet (64.5 centimeters) long and 2.44 feet (74.5 centimeters) wide. The nostrils are large, elliptical, and downward-facing; they cannot be seen from the front in fully-grown specimens due to the shape of the head. Its nasal passages are surprisingly complex, which may function for heat and water regulation or to amplify vocalizations. The size of its sinuses and the skull’s shape to accommodate them gives its snout a bulbous look. Overall the skull is wider than it is long, tapering to the front; because of its shape, the eyes do not face directly to the sides and instead look slightly forward. Its eyes are round, not particularly large, and have birdlike pupils; the iris may be brown, green, or blue, while the sclera color ranges from quite dark to a light yellow. The snout is arched and truncated, markedly different from other ankylosaurs. On the front of its head, on the premaxillae, it has a toothless beak which it uses to crop food. Farther back in its mouth it does have teeth, with about thirty-five in the maxilla as well as another thirty-five or so in each dentary. These teeth are phylliform, or leaf-shaped, in fossils; InGen specimens appear to have flatter molariform teeth, an aberrant trait also seen in InGen’s Stegosaurus. Its tongue is pink or reddish, U-shaped, and muscular, supported by bones called hyobranchia. This dinosaur appears to have cheeks: it is unknown whether the original creature had these, since fossil evidence has not revealed them yet. Therefore, it is uncertain whether InGen’s ankylosaurs’ cheeks are natural or a result of genetic engineering.

This dinosaur’s impressive armor begins on its head, including even its eyelids (formed from the palpebral bones). On the surface of its skull, bone remodeling leads to the development of scale-like features called caputegulae. As these form, they obliterate the rigid joints of the skull, fusing the bones. Ankylosaurus has several main caputegulae: the nasal caputegulum, which is hexagonal or diamond-shaped and located between the nostrils; the loreal caputegulae, strap-shaped and located on either side of the nasal; two supraorbital caputegulae (anterior and posterior) located above each eye; and finally multiple nuchal caputegulae forming a ridge at the back of the skull. Ankylosaurus also has four pyramidal horns at the rear of the skull. Two of the horns are formed from its squamosal bones, merging with the crests above its eyes and pointing outward and backward. The other two horns form from its jugal bones, pointing downward and backward.

While its heavy armor makes for a near-impenetrable defense, it makes Ankylosaurus a very poor swimmer as it quickly sinks in water.

While several fossil skeletons have been found, its postcranial appearance is still mostly undiscovered, so InGen’s cloned specimens are currently our only source on features such as its pelvis, feet, and much of the tail. Therefore, information on those body parts should be taken with the caveat that genetic engineering may have influenced their appearance. Still, the overall shape of this dinosaur is similar to what fossils demonstrate; it is a rather fat quadruped, its wide body supported by thick, stocky legs. Armor is its defining feature and covers the entire dorsal side, including cervical half-rings forming a kind of plated belt around its neck. Its body armor is covered with plates and knobs called osteoderms, which are sheathed in keratin. In fossils these are thin-walled and hollowed on the underside, smoother than those of some other ankylosaurs such as Euoplocephalus, though InGen Ankylosaurus are noticeably pricklier than their ancestors. In the modern Ankylosaurus, the osteoderms include the usual bony plates as well as six to eight rows of conical spikes. The spikes near the front and back of the body are shortest, while the longest appear in the middle; similarly, the spikes higher on the back are smaller, while those on the flanks are larger. Only one or two pairs of spike rows may continue all the way down the tail, with others disappearing as the body tapers. In the original animal, the osteoderms were ovoid or tear-shaped, and some were keeled, but none were shaped like conical spikes. However, other ankylosaurian species did have spiked osteoderms, suggesting that genetic contamination occurred in InGen Ankylosaurus with some of its relatives.

Osteoderms on Ankylosaurus are vascularized and may play a role in thermoregulation, similar to those of modern crocodilians. This also means that they can sense touch, rather than being devoid of touch receptors as one might assume. Ankylosaurus can feel physical sensations on their armor and can sometimes be seen scratching to relieve itches.

The legs of this dinosaur are quite robust as to support its weight, featuring broad humeri and thick femurs. Its hind legs are longer, but its front legs bear most of the weight. Each hind foot bears four toes, unlike most of the advanced ankylosaurs, and the front feet each have four toes as well. All of the toes are short and stubby, bearing small round claws. This is not a dinosaur built for speed, and while it can manage an ungainly gallop when frightened, it cannot maintain this movement for long and will often stumble if it tries to run. Its bulky armor and squat build make it an exceptionally poor swimmer. Most of its muscle is dedicated to supporting its large head and heavy tail, both of which are weighed down by armor. Only the underbelly and legs lack osteoderms, bearing instead the pebbly scales common to many dinosaurs. InGen’s specimens may have different hip and tail muscles than their ancestors, as their tails sometimes droop downward in ways that the original animal’s tail could not.

Said tail is, of course, what makes Ankylosaurus famous, bearing a bony knob-shaped club on the end measuring 2 feet (60 centimeters) long, 1.87 feet (57 centimeters) wide, and 7.5 inches (19 centimeters) tall. It is mostly semicircular when viewed from above, comprised of four main osteoderms (two large ones forming the base, and two small ones at the tip) with a row of small osteoderms on the midline. These obscure the last vertebrae of the tail, and the seven vertebrae preceding the club are fused together to strengthen it. The tail can be swung to generate around 400 megapascals of force, shattering bone upon impact.

Generally, this dinosaur’s color is a dark gray, with countershading on the legs and underbelly. Most show simply a lighter shade of gray for the countershading, but some are tan or brown instead. There may be red-colored skin around and below the eye orbits. Some demonstrate bluish tints to the smaller osteoderms and ossicles, while some show brownish-orange or greenish tints to the entire back. Rarely they may be light teal, rather than gray or brown, on the dorsal side. It is common for the tips of the osteoderm spikes to be whitish or very light gray as they wear down as the animal lives; the beak and tail club are also often lighter in color than the rest of the armor.


Ontogeny in Ankylosaurus is well-documented in InGen specimens. The dinosaur hatches at just a few inches in length, with the tail club already formed but proportionally small and the armor features also smaller. The osteoderms start out as rounder in shape, sharpening as the animal gets larger. This is in contrast to fossil Ankylosaurus, in which larger specimens appear to have blunter squamosal horns than the smaller animals.

During the juvenile stage, the body grows rounder and the tail does not immediately grow out to keep up; the head, on the other hand, is proportionally large, with big eyes. Since the tail is disproportionately small while the head and body are very rotund, the dinosaur at this age can essentially resemble an armored meatball on stubby legs.

Younger juvenile Ankylosaurus illustrations by Shaun Keenan

As it grows, the bones of the Ankylosaurus begin to fuse, beginning in the front and progressing toward the tail. This reinforces it, strengthening its defense and offense at the expense of its agility. Its forelimbs become stronger to support the added weight. Because of this, juvenile Ankylosaurus are faster and more nimble than the adults. In adolescence the tail catches up with the rest of the body as the bone remodeling process concludes, and the animal achieves its adult proportions.

This dinosaur’s coloration remains consistent throughout its life.

The natural growth rate is unknown, since most cloned specimens were treated to accelerated growth patterns as to reach adult size very quickly (going through adolescence in as little as a month). It is also not known how long these dinosaurs can live, but larger species tend to have decently long lifespans. The longest-lived InGen specimen confirmed so far was an eighteen-year-old female which hatched in approximately 2000; this ankylosaur was still alive as of early 2018 and may still be living if it was removed from Isla Nublar that year.

Sexual Dimorphism

So far, there is no reliable way to sex an Ankylosaurus without invasive observation.

Preferred Habitat

A reclusive species, Ankylosaurus is seldom seen in the open and strongly prefers heavily forested environments including jungles and cloud forest. In prehistory, it is believed to have inhabited subtropical and temperate wooded uplands, tolerating monsoons. As its low center of gravity means it cannot easily push down trees and it is unable to chew bark, it must live in regions where low-growing plants abound. Ankylosaurus is also typically seen in wet regions, near sources of fresh water, but avoids oceanic coastlines and is instead usually found in inland areas with packed soil. Its build makes it more suited to flatland than mountains.

As far as temperature goes, Ankylosaurus can tolerate a decently wide range. It was originally native to temperate to warm regions, but has acclimated quite well to the tropical environments in the Gulf of Fernandez where hot temperatures are common. It can also tolerate chilly conditions for limited amounts of time, relying on its large body size to retain heat.

Muertes Archipelago

Although InGen had obtained samples of Ankylosaurus DNA and had reconstructed 91% of its genome based on viability rate, there is no evidence that any had been cloned on Isla Sorna by the time the island was abandoned in late 1993. Deleted concepts from The Lost World: Jurassic Park suggest that at least one herd of this animal had lived on the island, but was extinct by 1997; official InGen documentation states that no Ankylosaurus were living on the island at the time it was abandoned, suggesting that if any such re-extinction event occurred, it happened while InGen was still operating on Isla Sorna. No specimens have been sighted elsewhere in the Muertes Archipelago.

This dinosaur was first confirmed to have been cloned between late 1998 and mid-1999. At the time, de-extinction was explicitly illegal due to the Gene Guard Act of 1997; InGen created this species in violation of the law, along with Corythosaurus, Ceratosaurus, and Spinosaurus. It appears to have inhabited the western region of Isla Sorna, living among banana groves and dense hardwood jungles. Those cloned in the late 1990s were subject to rapid-growth formulas which allowed them to begin breeding as early as 2000. At least one female hatched between May 16, 1999 and May 15, 2000, and a mated pair of adults with two juvenile offspring were confirmed by Eric Kirby at a cliffside stream near a banana grove in the morning of May 24, 2001. Two other pairs of adults were seen later, one pair near the Embryonics, Administration, and Laboratories Compound at dusk on July 18 and another pair in a clearing at the island’s central channel in the late evening of July 19.

Although the illegal cloning on the island had come to a halt in 1999 and was abandoned due to fears of discovery, it had already had a devastating effect on Isla Sorna’s precarious artificial ecosystem. The numerous new dinosaurs consumed vast quantities of food, leaving precious little to go around; by 2004, the island was in steep decline. At least one adult female Ankylosaurus survived this harrowing time, as did six eggs which hatched into female ankylosaurs in 2004 (either before or after being removed from the island). The surviving animals were transplanted to Isla Nublar by Masrani Global Corporation. Official records claim that no dinosaurs remain on Isla Sorna today, though reports of poaching among the Muertes Archipelago persisted through the 2010s.

Isla Nublar

This dinosaur was first introduced to Isla Nublar in 2004, with six juvenile females being brought to the Hammond Creation Laboratory by early August. They were not bred in the lab; instead, these were animals rescued from Isla Sorna either as eggs or juveniles and transported to Isla Nublar. These juveniles were each named after famous historical female warriors, though their exact names are currently unknown. Masrani Global Corporation planned to introduce them into the central valley where they would be visible from the Gyrosphere attraction, but issues with the territorial Triceratops delayed their debut.

By 2014, plans to finally incorporate the adult ankylosaurs into the valley were nearly complete, and they were advertised on the Jurassic World website by November. At the time, there were at least four adult Ankylosaurus living in a Sector 5 habitat, while a further twelve adults were members of Herd M present near the Camp Cretaceous Observation Tower. The members of Herd M spent their days grazing, and rested overnight in designated paddocks.

Unfortunately, no Ankylosaurus were ever successfully introduced to the valley while the park was in operation. The last member of this species to be hatched for the park was a female named Bumpy, who came into the world on December 20, 2015 in the field genetics laboratory. Bumpy can be told apart from other ankylosaurs by the shape of her squamosal horns; her left horn is smaller than her right. This feature was met with disapproval by her creator Dr. Henry Wu; although she had hatched prematurely, Dr. Wu ordered that she be administered growth-boosting hormones and released into the Sector 5 herd instead of waiting the standard three-month nursing period. Bumpy was adopted by one of the females in Sector 5. Her eight egg-siblings, who were also only ten weeks old, did not hatch prematurely and remained incubating in the lab.

On December 22, 2015, the Sector 5 herd was attacked by an escaped animal, the genetically-engineered Indominus rex. While the dinosaurs tried to flee, Bumpy’s adoptive mother stumbled and fell and was forced to face the predator. Sadly, having never fought for her life before, she was defeated by the intelligent carnivore and killed, leaving Bumpy an orphan. Not long after, Bumpy was found by Ben Pincus, a human she had imprinted on, and brought southward to Main Street via the Jungle River. The park was closed down and most of the power was turned off, so the eggs incubating in the lab most likely died.

The other Ankylosaurus, no longer restricted by their tracking implants as the park was shut down, began to roam the north of the island freely. They mostly remained near their old habitats, but expanded their range to seek out sources of food and water. During the night of December 22, Bumpy became stranded near the Jurassic World Golf Course; she remained there for nearly two months, during which time she matured from an adorable juvenile into a wonderful young adult. With her newfound strength, she was able to aid Ben Pincus in moving northward and surviving the hazards of a newly-wild Isla Nublar. Remaining alongside her human companions, Bumpy returned to the north in early 2016. She traveled between the northern and western regions of the island throughout the next few months; in June, she lived closer to the central valley with a larger herd of adult Ankylosaurus. Eventually she was forcibly removed from the island by Mantah Corporation operatives.

Ankylosaurus in defensive position. Its armor protects it from most predators, and its tail can be used to bludgeon attackers.

By mid-2018, the Ankylosaurus range had expanded to include the Golf Course and its surrounding area, with the nearby Botanical Gardens probably providing ample food for these herbivores. Many others remained in the north where they were originally housed, particularly in the eastern part of the island and around Mount Sibo. The volcano’s increasing activity caused magnetic disturbances from 2017 onward which drew some of the dinosaurs northward, probably including some of the Ankylosaurus.

On June 23, 2018, a total of ten adult Ankylosaurus were sighted near Mount Sibo and were driven eastward by its eruption on that day. None of them appear to have been from Herd M, indicating a larger size to the Sector 5 herd than those seen in 2015. They were forced to either suffocate in the toxic gases and clouds of ash or plunge hundreds of feet over the northeastern cliffs into the sea, where they would surely drown. Even the ankylosaurs living in the south would have suffered as their food sources were incinerated, leaving them to starve. This dinosaur has almost certainly become extinct on Isla Nublar due to the eruption.

The exceptions to this unfortunate fate were those removed from Isla Nublar. Among them were three adults who had been captured by a mercenary team led by Ken Wheatley at the behest of Eli Mills, benefactor to Henry Wu. Two had been captured prior to the eruption, while a third was loaded onboard the S.S. Arcadia during the eruption itself. This animal was logged into the ship’s manifest at 13:42, cosigned by James Fleming, and was held in Container #27-1008-3875 (Cargo #48863). This animal was weighed at 6,375 kilograms at that time, making it on the heavier end of the scale and therefore a healthily large adult.

Mantah Corp Island

Several species of de-extinct animals were captured or bred by Mantah Corporation, a rival to InGen, and held at a facility on the privately-owned Mantah Corp Island. Initially, no Ankylosaurus were among them, but in June 2016, an adolescent female from Isla Nublar called Bumpy was captured by Mantah Corp operatives and brought to Mantah Corp Island. She was not a part of the deal with BioSyn Genetics, but rather a form of leverage meant to be used against six teenagers who were interfering with Mantah operations. After the events of June 2016 which ended Mantah Corp functions on the island, Bumpy was allowed to live freely in the redwood forest biome, where she remains to this day.

Biosyn Genetics Sanctuary

After de-extinct animals were released into the wild on June 24, 2018, InGen’s rival Biosyn Genetics began vying for the right to capture and house the animals. Granted this right by international governments, they began shipping captured animals to facilities such as the Biosyn Genetics Sanctuary in Italy. Ankylosaurus is known to be one of the species they secured there.

Small groups of Ankylosaurus inhabited the low-lying forested areas of Biosyn Valley, usually near its several water sources. In the winter of 2022, a wildfire forced Biosyn staff to evacuate the dinosaurs to emergency containment, keeping them there until the fire subsided. Due to corruption among Biosyn’s executive ranks which was exposed after this incident, the United Nations assumed the position of monitoring entity over the valley.

Black market
Ankylosaurus at black-market auction, Orick, CA (6/24/2018)

In the years following its creation in the late 1990s, Ankylosaurus and other de-extinct animals in the Gulf of Fernandez were subject to poaching. Details about these early illegal ventures are scarce, so it is not known if these animals fell into the hands of exotic animal owners or other unsavory types. The first confirmed case of successful Ankylosaurus poaching was in June 2018, when financier Eli Mills hired mercenary hunter Ken Wheatley to capture numerous Isla Nublar animals for sale on the black market. They were held on the night of June 24 at the Lockwood estate; an adult Ankylosaurus was among those animals sold, going to an Indonesian buyer for US$10,000,000. A case of DNA samples including this species was sold to a Russian buyer, likely the notorious mobster Anton Orlov. Two others were still being held at the estate when a hydrogen cyanide leak occurred, leading to their release from the manor.

Now that they have entered the wider world, their genetic material has become more easily obtained by anyone with enough money. Ankylosaurus have been bred, captured, and shipped around the world through covert venues. One of the biggest hubs of de-extinction trade is the Amber Clave night market in Valletta, Malta.

Wild populations

Ankylosaurus was originally a North American dinosaur, evolving on the continent about 68 million years ago. It is known to have lived in forested areas in the northern and western parts of North America, though the poor quality of fossil-bearing rock in the east mean that it could have lived here too and simply never fossilized. Part of the reason for this might have been that it lived in uplands, rather than near coasts where fossilization is easier. Nonetheless, it seems to have been a rare dinosaur with lower population levels. It persisted until the bitter end of the Cretaceous period, when a mass extinction event wiped out virtually all megafauna including Ankylosaurus. 66 million years later, scientists located samples of its DNA which were used to clone it, though genetic modification was necessary in order to construct viable genomes to utilize. Therefore, the descendants were artificially altered from their original biology.

There is currently no concrete evidence that Ankylosaurus was captured or transported to the mainland prior to June 24, 2018, though the possibility certainly stands. As is currently known, the first case of Ankylosaurus on the mainland was the capture operation held in 2018, which transported three adult ankylosaurs from Isla Nublar to the Lockwood estate near Orick, California. The animals were held in the sub-basement laboratory overnight on June 24. Two ankylosaurs were still being held in the laboratory when a hydrogen cyanide leak threatened their lives; they were released by Maisie Lockwood, fleeing into the surrounding redwood forest. In the ensuing weeks, one of them was sighted aggressively competing for territory with a Triceratops near Folsom, California. Some also migrated to Big Rock National Park, where at least two adults lived during the early 2020s. They still had not spread very far as of early 2022, when they were mainly reported from Northern California close to where they were released. Some were seen in national parks and other protected land such as the King Range National Conservation Area. Another adult was sighted in Enid, Oklahoma during an incident in late May 2022 in which it was panicked by traffic and flipped a Kirby Enterprises company car; the Department of Prehistoric Wildlife reported that ankylosaur activity was common around Enid. On June 10, a subadult was filmed by an Oregon State University student near the campus in Corvallis, Oregon. Farther north they have been known by the CIA’s dinosaur tracking division to inhabit woodlands between Lake Superior and the Lake of the Woods in Ontario. In the game Jurassic World Evolution 2, a pair of Ankylosaurus can be found near St. Louis, Missouri; they are said to have injured two civilians. They can be captured by the U.S. Fish and Wildlife Service and transported to the Dinosaur Housing and Transport Hub located in the Pennsylvanian Appalachians to be safely contained and studied before their final relocation.

These animals are sparse outside North America, but not unknown. A herd is being tracked by the CIA in Norway, where it inhabits the forests near Lake Mjøsa. This represents the only Ankylosaurus population in Europe. Two populations are known in Africa, one near Kediet ej Jill in Mauritania and one near the Targa Valley in Libya. These locations are on the outskirts of the hot and dry Sahara Desert, so the ankylosaurs of the region must find oasis lakes and other bodies of water capable of supporting them and the plants they eat.

At least one population is known in Asia. A family group of Ankylosaurus was sighted in early 2022 within Kanger Ghati National Park in India, having certainly been transplanted there by human intervention. They may have escaped from an illegal animal trafficking operation or a dinosaur breeder, or been intentionally released into the wild. According to locals reporting to the Department of Prehistoric Wildlife, the family’s breeding pair had recently produced new offspring.

Behavior and Ecology
Activity Patterns

Ankylosaurus is diurnal. It has a fairly regimented daily behavior pattern; in the morning it wakes at or just before sunrise to feed, then seeks out fresh water from which to drink. Eating and drinking takes up most of its time, and by sunset, it retires to sheltered spaces to sleep, preferring comfortable beds of fallen leaves and other soft natural materials. From time to time, it will bathe in bodies of water during midday.

Diet and Feeding Behavior

Like many dinosaurs, Ankylosaurus cannot chew, and so may possibly use gastroliths in order to help grind up its food. It is a bulky herbivore and spends virtually all of its waking hours searching for food, which consists of low-growing leafy plants such as ferns and shrubs. It may consume fungi, especially those that grow on rotting wood and other plant foods it already eats. The diet of this dinosaur also includes fruits such as berries, and it uses its senses of smell and taste to determine which fruits are safe to eat and which are harmful. With a wide muzzle evolved for generalist browsing, it crops plants at the stem and swallows them in bite-sized pieces, taking in even tougher material. Tree saplings and cycads constitute a good amount of its diet, though it is best known for eating ferns.

Ankylosaurus adult browsing on plant life, Isla Sorna (6/18/2001)

An adult Ankylosaurus consumes 130 pounds or more of ferns in a day to keep itself fueled. This is comparable to the amount of forage taken in by a large African bush elephant (Loxodonta africana), though the Ankylosaurus can make its feeding more efficient by eating fruit. It could potentially also get additional nutrients by inadvertently consuming invertebrate animals, such as insects and worms, which live on and inside the plants it eats. Since it does not extensively chew its food (the jaw has only limited mobility), it has yet another means to be more energy-efficient than modern mammals; it probably employs hindgut fermentation to digest its food, similar to other herbivorous reptiles. The soft-canon book Jurassic World: Fallen Kingdom Survival Guide suggests that magnolias are among its favored food sources, along with other flowering plants.

Some paleontologists have suggested that the snout and muscular tongue of Ankylosaurus are adapted to help it dig in loose soil. This means that it could possibly dig up roots and tubers as food sources, or else that it may supplement its diet with worms, grubs, and other subterranean invertebrates. These behaviors have yet to be witnessed in live ankylosaurs.

According to Jurassic World: Evolution, the preferred food of Ankylosaurus is horsetails, while it also enjoys mosses and paw paws. It cannot digest tree ferns, conifers, or ginkgoes. This game’s sequel portrays it as requiring a mixture of leafy plants and fruit.

Social Behavior
Ankylosaurus is commonly seen in pairs or small groups.

This is not a very social dinosaur, usually seen in smaller groups; in the wild, it is most commonly seen in pairs or small herds of up to four adults and their offspring. InGen has succeeded in keeping them in herds containing up to twelve animals, but this is generally only seen in captivity or when natural events force multiple ankylosaur social groups together. Smaller environments may also prompt ankylosaurs to form larger social groups, though they do not seem to suffer any ill effects from this. Ankylosaurus is not very intelligent (with a brain-to-body-size ratio similar to Stegosaurus) and has limited social interactions, mostly consisting of browsing for food together and emitting low-pitched, infrequent calls to maintain contact. They mainly congregate around nesting sites.

Unrelated adults will not usually defend one another in times of danger aside from giving warning cries if they spot a threat. However, adults will defend juveniles in their care, and once juveniles are old enough to defend themselves, they will aid adults they have imprinted on. This does not just include biological relationships: adult Ankylosaurus will adopt orphaned juveniles and care for them as though they were their own. Bonded individuals often sleep near one another; growing juveniles will gain comfort from physical contact with their parental figures.

Many paleontologists believe that the armored club tail of Ankylosaurus and its relatives originally evolved not as predator defense, but for intraspecific combat. Two rival animals could use their tails to pummel one another, their tough hides shielding them from the worst of the blows. This form of combat may settle disputes such as mating rights or positions of dominance in a social unit. This is depicted in the Jurassic World: Evolution games, both in and out of combat. For example, one ankylosaur will sometimes accidentally hit another with its tail as it passes by, earning it a retaliatory but not combative whack to the flank in response.


The eggs of Ankylosaurus are rounded ovoids, not as oblong as theropod eggs, but more so than those of sauropods. They are off-white in color and similar in texture to the eggs of many modern birds. Larger dinosaurs lay eggs which take six months to a year to hatch; an egg which hatched after ten weeks was described as significantly premature. It is uncertain when Ankylosaurus breeds, though small juveniles in the wild on Isla Sorna have been observed in May. This suggests that eggs hatch in the spring, or what in Costa Rica would be the rainy season. Ankylosaurus eggs are about the size of a human head, and the hatchlings begin life at around the same length.

Courtship behavior has not yet been observed, but most likely involves males displaying their defensive and offensive capabilities. Those with tough armor and strong tails would make more desirable mates, since they have traits that help them survive. While the Ankylosaurus most likely has a cloaca like the majority of dinosaurs, exactly how this portly creature mates is still unknown.

The world is instantly improved by the hatching of Bumpy, Isla Nublar (12/20/2015)

When the juveniles hatch, they imprint immediately upon the first creature they see, suggesting that adult ankylosaurs guard their nests and provide parental care. The hatchlings may break through their eggshells using their tails in addition to their heads and limbs. From an early age, Ankylosaurus forms bonds with its parental figures, relying on them for protection from predators and becoming distressed if separated from them. It uses a specific distress cry to call to its parents and other adults. The parental figure may not be the juvenile’s biological parent; like many other ornithischian dinosaurs, Ankylosaurus without offspring of their own may adopt orphans.

Although Ankylosaurus does exhibit parental care, the juveniles become capable fairly quickly and can learn to defend themselves through instinct alone. By the time a juvenile Ankylosaurus reaches four or five feet long, it probably exceeds a hundred pounds in weight and is able to use its stubby tail to fend off small predators. Its armor provides it with protection from above, though it is not fully fused and may still be vulnerable to attack from larger animals. On the other hand, its incompletely-fused skeleton means it is more agile and maneuverable than a fully-grown adult, so young Ankylosaurus are faster. They may tire out more quickly, though, as their growing bodies need lots of fuel; the young spend more of their time sleeping than the mature adults.

Herd of mature Ankylosaurus protecting a young adult

Historically, InGen has used growth-accelerating hormone supplements to force Ankylosaurus into early maturation. This causes it to reach skeletal maturity in as little as a month. Its natural growth rate is unknown at this time, but its familial bonds persist into adulthood, suggesting that multigenerational social groups would exist in nature. Young adults have been witnessed defending their parental figures from threats, implying that in a multigenerational herd, the older dinosaurs may be cared for by their own adult offspring. This would allow the older Ankylosaurus to live longer lives, kept safe from danger by the younger animals they once raised.


As a simple creature, the Ankylosaurus has a reasonably unsophisticated set of communications that it uses among its own kind. These mostly consist of low-pitched grunts, groans, and growls; they are emitted periodically while the animals feed and travel together, so they are probably used mainly to keep in touch and reaffirm their familial bonds.

The juvenile uses higher-pitched squealing noises to gain the aid of the adults. It emits distress cries when it is separated from its parents, which draws the adults back to its side. Juvenile Ankylosaurus also cry out when they feel threatened, such as by a predator. They are known to vocalize in the morning, which serves to wake up their family members so that feeding and drinking can take place as a group. For the juveniles, remaining as a group is highly beneficial since the adults can better defend them against large predators.

Adult Ankylosaurus emitting a defensive threat call

The Ankylosaurus is territorial and moderately aggressive, and so it has a number of threat displays it can use for both intraspecific and interspecific combat. Among the most common is thwacking its tail club on the ground, producing a loud banging noise and demonstrating the bone-breaking potential of the tail. When it strikes the ground, it may also dislodge and toss about rocks and other objects, further highlighting its dangerous power. There are territorial vocalizations as well, including low-pitched bellows and roars. It often uses these vocal threats in conjunction with the tail-slamming display. The meaning of these demonstrations is universally understood and can be used against rivals of the same species, rivals of other species, and predators.

Ecological Interactions

Aside from the ferns and other plant life upon which it feeds, Ankylosaurus is a recluse and prefers to avoid other living things as much as it can. If confronted with a threat, it can respond with a menacing display of strength using its tail, which can be swung at the legs or head of an attacker to deal serious injuries. An adult swinging its tail at full strength can shatter bone. This is especially hazardous to theropod dinosaurs, whose bones are hollow. If a predator suffers a broken leg, it may be unable to hunt and might starve. Only the most fearsome of hunters ever attempt to prey on Ankylosaurus; both Tyrannosaurus and Carnotaurus have been observed making efforts to take down young adults, but neither succeeded. Only the genetically engineered Indominus rex has ever been known to successfully kill a fully-grown Ankylosaurus. Even the smaller relative of Indominus, the Scorpios rex, is powerless against a determined ankylosaur; its venomous barbs cannot puncture this creature’s thick armored hide.

Juveniles are more vulnerable to predators, as their tails cannot yet break bone. Younger juveniles may be attacked by Pteranodon, which could potentially kill a juvenile by lifting it into the air and dropping it. Particularly determined swarms of Compsognathus can pose a threat to juveniles as well. On the other hand, though, compies can also benefit by eating the dung of ankylosaurs, which keeps the environment clean. Other predators known from ankylosaur territories include Velociraptor, BaryonyxMonolophosaurus, Allosaurus, TeratophoneusCeratosaurus, and Spinosaurus, all of which may threaten at least younger Ankylosaurus. It can also be harassed by parasites such as mosquitoes, which bit this dinosaur in the Cretaceous period and probably continue to do so today. Although its body is armored, it still has sensitive exposed membranes such as the insides of its nostrils where mosquitoes could bite it. In the game Jurassic World: Evolution, this dinosaur is particularly susceptible to Cryptosporidium infections, though it is never known to host Campylobacter.

So far, the genetically-engineered Indominus rex is the only theropod witnessed successfully hunting down and killing a mature Ankylosaurus. The exposed underbelly is this herbivore’s only real weakness.

This dinosaur does not just face threats from predatory carnivores: it is protective of its personal space, and faces stiff competition from herbivorous dinosaurs. For the most part, it avoids competition by being a generalist browser, not specializing on one particular plant species. This enables it to move into any habitat it chooses, helping it avoid competitors. Still, on small islands such as Isla Nublar and Isla Sorna, Ankylosaurus often runs into its neighbors. It has been observed tolerating the presence of the iguanodont Ouranosaurus, the hadrosaur Parasaurolophus, the sauropods Brachiosaurus, Diplodocus, and Apatosaurus, the pachycephalosaur Stygimoloch, the ornithomimid Gallimimus, and its fellow thyreophorans Peloroplites and Stegosaurus. Most herbivores do not intentionally bother Ankylosaurus, but they may aggravate it by accident, such as accidentally bumping it or striking it by mistake during moments of panic.

It has also been noted living near the ceratopsians Triceratops and Sinoceratops, as well as potentially Pachyrhinosaurus. However, not all ceratopsians are ideal neighbors. Triceratops is also territorial like Ankylosaurus and has been witnessed engaging in combat with this armored giant. Juvenile ankylosaurs are sometimes harassed by Triceratops; this ceratopsian has been known to bully the juveniles of other dinosaurs to the point of starvation. Adult Ankylosaurus can withstand strikes from the bodily weapons of their competitors, and may fight back using not only their bony clubbed tails but the spiny osteoderms on their flanks. With these, a full-body side-shove becomes even more injurious.

Ankylosaurus may have difficulty getting along with other herbivores, since they compete with it for food.

Modern life forms also live alongside this de-extinct creature, such as various birds. These are usually not competitors, and instead can be mutualistically symbiotic. The ankylosaurs’ movements may crush plants and stir up insects, which the birds eat, and the birds can also consume pests such as ticks that might otherwise harm the ankylosaurs. Other modern animals have a less peaceful relationship with the Ankylosaurus. Eric Kirby noted in 2001 a large snake, possibly a common boa or a bushmaster, attempting to prey on a young juvenile ankylosaur.

While the ecological equivalent of Ankylosaurus is often considered to be the elephant, they are actually fairly different. The chief ecological difference is the fact that while the elephant is an ecosystem engineer, bulldozing trees and creating grassland in its wake, the Ankylosaurus has too low a center of gravity to do this. It feeds only on low-growing plants, unable to rear up to knock down large trees and unable to chew bark from trunks. Smaller trees may be knocked down by its bulk or by strikes from its tail, but fully-matured trees are unlikely to be felled. In fact, rather than creating grassland, the Ankylosaurus is far more likely to facilitate the spread of shrubs and trees, since it eats fruit. It therefore passes their seeds along in its dung. The forest benefits Ankylosaurus, and in return, the dinosaur expands the woodlands it inhabits.

Cultural Significance

Ankylosaurus is one of the best-known herbivorous dinosaurs and certainly the most common ankylosaur in paleoart, dinosaur encyclopedias, film, cartoons, and more. Its characteristically tank-like appearance gives it instantaneous appeal. However, it is often confused with its relatives, leading to it being illustrated with anatomical features it never actually had. This is also the case in a more literal sense with InGen’s specimens, which have been given the features of other ankylosaur species through genetic modification.

The gluttonous and shy personality of Ankylosaurus makes it a favorite of many introverts. One Ankylosaurus in particular, Bumpy, is the favorite of everyone everywhere and symbolizes all that is good in the world.

According to Universal Studios, Ankylosaurus is the dinosaur of the Scorpio astrological sign (October 23 – November 22).

In Captivity

Despite being one of the more popular dinosaurs, Ankylosaurus faced difficulty being integrated into Jurassic World due to the already-established presence of Triceratops. The park’s behaviorists feared that the territorial Triceratops would harass the juvenile Ankylosaurus if the latter was introduced to Gyrosphere Valley too soon, and if they were introduced too late, they would be powerful enough to severely injure a Triceratops in a retaliatory attack if harassed. Choosing the exact right time to integrate them into the valley was a challenge which delayed their introduction to the park.

Research into Ankylosaurus was ongoing behind the park’s restricted access gates for most of its time in operation, particularly involving Herd M. This social group integrated several species of herbivorous dinosaur, including more Ankylosaurus than a typical herd; however, there were no Triceratops in Herd M. While these dinosaurs were not destined for the park exhibits, they could be viewed from Camp Cretaceous, and they helped Jurassic World’s animal behaviorists better understand this creature’s needs. Several other Ankylosaurus were held in Sector 5; these are believed to be the ones meant for eventual introduction to Gyrosphere Valley. So long as it is kept in appropriate conditions, Ankylosaurus appears capable of basically providing for its own needs, reducing costs necessary to keep them fed and comfortable. Its main health issue appears to be constipation, which can make it uncomfortable and aggressive.

The ankylosaurs’ moderate levels of aggression were not only a concern when it came to the other dinosaurs; a swing of their tail can easily kill a person, even unintentionally. Ankylosaur tails have been known to damage gyrosphere hulls, which are made from aluminum oxynitride glass tested to withstand 20-caliber bullets. Gyrospheres were equipped with chips that would keep track of how close they were to the park dinosaurs, which were also chipped; upon coming too close, a dinosaur would be administered a minor electric shock and the gyrosphere would automatically roll back. Still, these precautions were not foolproof. Despite the difficulties, Ankylosaurus was advertised on the Jurassic World website as of late 2014 as being in the Gyrosphere attraction, suggesting that the park’s animal specialists had determined the best way to integrate them and were planning on doing so in the coming year.

Unfortunately, the park closed before Ankylosaurus could be integrated, leaving them restricted to the island’s north. The only ankylosaurs visitors would have ever seen would have been those hatched in the Hammond Creation Lab, which were destined for Sector 5 after a three-month period in the nursery.

Ankylosaurus were also being bred in the field genetics laboratory for Dr. Henry Wu‘s personal research. The last of these to hatch was a female named Bumpy, who hatched prematurely with asymmetrical squamosal horns. This feature was seen as a defect by Dr. Wu, who dismissed Bumpy as an inferior specimen in what was arguably the most morally bankrupt act of his entire career. Bumpy’s uniqueness was properly appreciated by one of the Camp Cretaceous members, Ben Pincus, who took care of this completely perfect dinosaur and protected her during the 2015 incident. Bumpy grew rapidly into a young adult due to the hormones administered by Dr. Wu’s lab staff, and soon returned the favor to Ben by protecting him from danger as well. Bumpy has continually proven that she is the best dinosaur ever to be hatched.


Fossils of Ankylosaurus are disappointingly rare, with only one of the skeletons actually including the famous tail club. Still, paleontologists have learned much about the ecosystem of North America at the very end of the Cretaceous period from this dinosaur’s remains, including the ways in which animals evolved to survive the most powerful terrestrial predators alive at the time. This dinosaur lived alongside many other well-known species such as Tyrannosaurus and Triceratops and probably interacted with them. There were other ankylosaurs in its ecosystem, but Ankylosaurus itself appears to have lived in different regions, likely upland areas where it would avoid competition. This may be due to either niche partitioning or competitive exclusion, which are both important concepts in ecology which describe how different species impact one another.

Ankylosaurus is a very derived ankylosaur with noticeable skeletal features that make it unique among its lineage. The rarity of its fossils mean that scientists have limited information about just what it looked like; many parts of its rear body have yet to be found. Some speculation about its lifestyle can be made, such as the hypothesis that it may have dug into the ground using its snout or tongue to look for food.

Since its de-extinction, Ankylosaurus has gained importance as the first ankylosaur to be brought back to life. It is a prized addition to InGen’s genetic library and has furthered research into dinosaur genetics, behavior, and biochemistry. As one of four species illegally bred during a time when InGen was experimenting with new technologies and methods, it played an instrumental role in the development of modern growth-acceleration techniques. These were used extensively in Jurassic World to create mature animals at incredible speed.


Ankylosaurus became a threat to Masrani Global Corporation during the government investigations in late 2015 and 2016 surrounding alleged violations of the Gene Guard Act in the late 1990s. Along with three other species, Ankylosaurus was cloned during a time in which de-extinction was explicitly outlawed by the United States government. Masrani Global attempted to bury the existence of these species in 2001, but Ankylosaurus was still mentioned in Survivor despite their efforts. Ultimately, its existence was known to the public in 2004, when this dinosaur was brought to Isla Nublar; it is the only one of the four illegal species which is confirmed to have not gone extinct after 2015 as well, making it the most successful of them.

This dinosaur is widely popular, making it one of the common features in Dinosaur Protection Group material in 2017 and 2018. During those years, this dinosaur’s existence was threatened by volcanic activity on Isla Nublar. The DPG was not the only party to recognize the popularity of Ankylosaurus. During the supposed rescue mission financed by Benjamin Lockwood through his foundation’s manager Eli Mills, lead hunter Ken Wheatley captured at least three adult Ankylosaurus which Mills intended to sell on the black market for their unique biopharmaceutical properties. The defensive capabilities of Ankylosaurus were among its selling points. While in Wheatley’s possession, some of the Ankylosaurus were mistreated. This was the first dinosaur sold during the auction on June 24, 2018; the other two may have been held for later. The Ankylosaurus sold for US $10,000,000 to an Indonesian bidder, and was presumably shipped to Indonesia shortly thereafter. Later dinosaurs sold for increasingly higher amounts as the bidders became more and more excited; however, the potential sales prices of the other ankylosaurs was never determined as the auction was disrupted by animal rights activists from the DPG. The remaining animals had to be released due to a hydrogen cyanide leak.

Since then, Ankylosaurus has been introduced to the Pacific Northwest. It does not generally venture into human-inhabited areas, but has been seen on rural roads. Although it avoids people, it may still be a hazard to vehicles since its tail club and sheer bodily bulk can easily disable most machines.


InGen intended to exhibit this animal in Jurassic World, where it would make an interesting new addition to the Gyrosphere Valley environment. Tourists would be able to see these dinosaurs up close from within gyrospheres, which would theoretically keep them and the animals safe from each other. Unfortunately, Ankylosaurus never made it to exhibit, since Jurassic World closed in late 2015. Therefore its potential as a park attraction has not been tested. InGen did seem to believe it was likely to be a huge hit, though, since efforts to establish this dinosaur were underway from 2004 until the day the park closed. As of November 2014, it was advertised on the park website and seen on various merchandise, suggesting it was nearly ready.

Along with its appeal to tourists, Ankylosaurus is valuable to science and forest ecology. Since fruit makes up a large amount of its diet, it is an important distributor of seeds, and has the ability to efficiently spread woodland wherever it lives. Humans may benefit by researching its physiology as well, since all de-extinct and genetically engineered life yields biopharmaceutical compounds not found in modern, unmodified life forms. The compounds that can be sourced from Ankylosaurus have not yet been determined, but the potential for this use drove Lockwood Foundation manager Eli Mills to list this species for black market sale. Several were captured by his lead hunter Ken Wheatley, who harvested teeth from his captured animals as trophies. The living ankylosaurs were advertised for their defensive capabilities, suggesting that they might be used for bioinspired defense technologies. Bioinspiration is a major growing scientific field, basing new developing technology on patterns that occur in nature and accomplish similar goals. An adult Ankylosaurus may sell for at least ten million U.S. dollars on the black market; Mills intended to use this money to finance Henry Wu‘s research.

Last but far from least, Bumpy the Ankylosaurus is the greatest resource we could ever dream of. She is a treasure to be valued by all of humanity and a priceless gift to the world. She betters our lives simply by existing in her state of dinosaurian perfection. Bumpy warms the coldest heart and makes every life worth living.


Ankylosaurus is one of the most thoroughly defended of all dinosaurs, and it is (both literally and figuratively) hard to get under its skin. This does not mean you should approach it if you encounter one in the wild; its defenses can easily be turned to offenses if it feels threatened. Remember, this is a dinosaur that evolved to fend off Tyrannosaurus rex and live to see another day. It took an impact event one hundred million times more powerful than the most destructive thermonuclear weapon ever developed to kill this species. Ankylosaurus is built to survive.

You are most likely to encounter one in forested areas, since this is where it likes to live, and this is where its food grows. So long as you keep your distance, it may be safe to observe them while they forage. You will likely find them in areas where the underbrush and saplings have been cleared by browsing, and where larger trees are broken or bent by their bulky bodies. Ankylosaurus is large, but not tall, and may be partly concealed by shadows or foliage; remain alert when in woodlands, especially near bodies of water or fruit-bearing plants. These will attract animals. If there are ankylosaurs nearby, do not startle them, for example with loud noises, bright lights, or making sudden movements. This goes double if there are juveniles; Ankylosaurus is extremely protective of its young and will be more aggressive than usual if defending them. If you must approach, do so from the front, remaining in its field of vision; if you approach from behind you risk startling it and thereby ending up on the wrong end of its bone-shattering tail. People traveling in a group should stay together. Do not spread out and crowd the dinosaur, and behave in a calm manner. Sudden movements, bright colors, and other startling sights can make it feel threatened. This means that approaching in a vehicle is also a bad idea.

Should you upset this dinosaur, it will probably start by making a threat display. The most common form is slamming its tail club into the ground, making a powerful thumping sound and clearly demonstrating how strong the dinosaur is. This is a serious and honest warning: back away, or it will break whatever bones it can strike. Even a threat display can harm you if it kicks up rocks or other debris, so you should already be putting distance between you and it. Rather than running, back away slowly with your hands visible but held low. If you run, the ankylosaur may be startled and attack you. These are simple creatures, so reasoning with them is not an effective method. Try to get the ankylosaur to calm down by behaving in a non-threatening manner, or distract it by drawing its attention to food sources such as ferns and magnolias. Once it has calmed, quickly and quietly leave the area. Do not try to intimidate it by shouting or waving your arms, since there are very few living things capable of intimidating an Ankylosaurus and you are not one of them.

If it does not calm down, it will probably charge, trying to flatten you. This is where your agile human body will come in handy: swiftly dodge to the left or right, whichever way is safer, and immediately make for shelter. Ankylosaurus is a wide dinosaur and has difficulty squeezing between close trees or into tight crevices, so use these to slow it down or lose it. Even just hiding may be effective, since once you are out of sight, it will eventually decide that the threat has passed and cease chasing you. If you manage to dodge its initial charge, continue to move away, since the clubbed tail will come into play next. In close quarters it can move more suddenly than you might expect; do not underestimate it and keep your eyes on its tail. On open ground you can probably outrun an adult Ankylosaurus, since they can only move quickly in short bursts. If you absolutely must physically defend yourself, and we strongly recommend this as only a last resort, know that its eyes are not a weak point as with most other dinosaurs. The eyelids are bony, making attacks to the eyes ineffective.

The exception to all of the above is Bumpy, who is benevolent. You will not be threatened by Bumpy, though you may have a heart attack from sheer cuteness.

Behind the Scenes

While not intended to appear in The Lost World: Jurassic Park, this dinosaur would originally have been mentioned by the character Dr. Robert Burke. In the film’s original script, Burke mentions seeing the remains of an Ankylosaurus herd while flying over Isla Sorna, surmising from the carcasses that this dinosaur has fallen back into extinction.

Unfinished CGI of three ankylosaurs in Jurassic Park ///

Deleted scenes involving Ankylosaurus are known from Jurassic Park ///, particularly one in which three Ankylosaurus cross the river on Isla Sorna in front of the InGen barge. Popular rumor claims there was a deleted scene in which an Ankylosaurus would fight several Velociraptors, but there is no evidence of this scene ever existing.

Notable Individuals

Bumpy – female Ankylosaurus hatched in 2015; the cutest dinosaur

Bumpy’s Mother – female Ankylosaurus involved in the 2015 incident

Auctioned Ankylosaurus – individual sold to an Indonesian buyer on the black market in 2018

Disambiguation Links

Ankylosaurus magniventris (JN)

Ankylosaurus magniventris (L/M)

Ankylosaurus sp. (IDW-DG)