Dilophosaurus, with a name meaning “double-crested reptile,” is a small to medium-sized species of theropod dinosaur in the family Dilophosauridae. It lived 196 to 183 million years ago, during the Sinemurian and Pliensbachian stages of the Early Jurassic. Three skeletons of this animal were discovered in the Kayenta Formation of Navajo County, Arizona in 1940, and two skeletons of excellent quality were found by Jesse Williams in 1942. Paleontologist Samuel P. Welles named it Megalosaurus wetherilli in 1954; the specific epithet honors Navajo councilor John Wetherill. In 1964, a more complete skeleton was discovered, including the skull. With the signature pair of crests now known to science, Welles assigned this species to a new genus, Dilophosaurus, in 1970.
The family to which this animal belongs, Dilophosauridae, includes a number of early theropods such as Cryolophosaurus, Dracovenator, and Zupaysaurus. Fossils of Dilophosaurus include specimens of varying completeness and ages; at least one fossil consisting of scattered fragments is believed to come from an infant. Fossilized footprints have been attributed to Dilophosaurus, giving some insight into how it moved.
There is currently only one known species of Dilophosaurus in the fossil record. A second species, Dilophosaurus sinensis, was named in 1993, but was later found to be the same as a previously-known species called Sinosaurus triassicus.
International Genetic Technologies succeeded in cloning Dilophosaurus from prehistoric amber sometime between 1991 and 1993. The specimens InGen created possess an atypically large number of phenotypic anomalies, believed to be a result of gene splicing. While the InGen IntraNet website identifies the specimens as D. wetherilli, Jurassic-Pedia has assigned a new specific epithet to distinguish InGen’s specimens from those known from the fossil record. InGen specimens are classified herein as Dilophosaurus venenifer, the specific epithet meaning “venom-bearing.” In common parlance, D. venenifer are sometimes referred to as “spitters” or “dilos.”
Jurassic Park: The Game implies that this species contains genetic structures from Hyperolius viridiflavus in its genome. However, it is officially confirmed to contain donor genes from Dendrobates leucomelas which integrated successfully before H. viridiflavus was ever even considered as a gene donor. It is not impossible that differing lineages of InGen Dilophosaurus may have had one or both of these frog species hybridized into their genomes. As of June 11, 1993, InGen had created up to Version 2.01 of this species.
Dilophosaurus reaches a length of 6 meters (20 feet) in adulthood, with a hip height of around 1.8 meters (6 feet) and a weight of 454 kilograms (1,000 pounds). This makes it a small or medium-sized theropod, but for the time period in which it originally lived, it was quite large. Around half its length consists of its lengthy, somewhat flexible tail. All parts of its body are slender, giving it a build suited for agile movement. However, D. venenifer is slightly smaller and heavier than D. wetherilli, which can reach 7 meters (23 feet) in length and is estimated to weigh around 400 kilograms (880 pounds). Many seem not to grow to their adult size at all, staying within the 8.86-foot (2.7-meter)-long range. Larger adults can look smaller than they actually are because they do not get as tall as most people expect, maintaining a low profile with the head near the ground; even at full size they do not generally raise their heads higher than a human adult’s eye level.
It has strong legs, with very large thigh bones and long, stout feet. Three of the toes bear large claws, with the first toe (or hallux) being much smaller and raised off the ground. All of these features give it a considerable running speed of 30 miles per hour, and enable it to travel with an unusual hopping gait as well as more conventional running. Like nearly all theropods, it is a biped. Dilophosaurus is very nimble due to its lightweight frame and strong legs.
The arms of this dinosaur are lanky but strong, like its legs. The hands have four digits, including an opposable thumb. The thumb is short, but bears a powerful claw. The next two fingers are longer and thinner with smaller claws. Its fourth finger is vestigial, serving no functional purpose; it appears to have been lost entirely in D. venenifer. Its arms are designed for grasping, and along with the feet, they are used for capturing prey. The wrists of this theropod are pronated, like most InGen theropod specimens but unlike those in the fossil record.
Of course, the most distinctive feature of this dinosaur is its skull, placed on the end of a relatively long and slender neck. Dilophosaurus is characterized by its pair of thin plate-shaped lateral crests, which form a V-shape when viewed from the front. They are semicircular, each with a small pointed prong on the back, and constitute about half the height of the skull; they are larger in D. venenifer than in fossil specimens of D. wetherilli. The jaws are large, filled with thirty sharp, serrated teeth. Larger teeth are situated in the back, with smaller ones at the front. These are not as robust as in later, larger theropods, but are not as fragile as commonly assumed; they would be replaced throughout life. Its upper jaw possessed a gap or “kink” just below the nostril, which is smaller in D. venenifer than in fossils, but not absent. The jaws are narrow in the front and wider in the back. The tongue is large and triangular, with a purplish color, and the nostrils and eyes both face forward.
Several anatomical features are present on the head of D. venenifer which are not known from any fossil specimens. These include an extendable cowl or frill around the neck similar to that of the frill-necked lizard (Chlamydosaurus kingii), which is supported by cartilaginous rods attached to the neck. This normally lies retracted flat against the neck, but can be unfurled by the animal and flushed with color. When unfurled, the cowl has a diameter that easily more than triples the width of the head, and bears a serrated edge. Muscles on the throat permit the cowl to be vibrated when extended. A second feature of D. venenifer not present in D. wetherilli is a set of venom glands in the mouth; while some concept art portrays these as being located underneath the lower jaw, their actual placement is not known. Dark-colored hemotoxic and neurotoxic venom is squeezed out from underneath the tongue and expelled at high speed from the mouth, striking with reasonable accuracy at distances of fifteen to twenty feet (up to six meters) in juveniles. The magazine Jurassic News suggests that an adult could strike accurately up to fifty feet (about fifteen meters) away. While soft-tissue features such as these would not fossilize, Dr. Laura Sorkin as well as multiple accessory sources indicate that the cowl and venom glands are an unintended result of genetic engineering. These include a queue video from the Jurassic World ride, in which Dr. Henry Wu himself confirms that the abnormal features are unintended results of genetic engineering.
Dilophosaurus features cryptic coloration, meaning it is suited for camouflage. It inhabits forested areas, and thus has a body which is forest green in color with darker green splotches on the back, legs, and crests. Alternative depictions have shown it with reddish-brown splotches, rather than dark green ones. The cowl is brilliantly colored; when flushed with color it appears bright yellow with intricate red patterning. Some individuals show green or magenta shading to the cowl. Alternative depictions show a yellow-gray cowl color with a solid red-brown ring around each flap. Unused shots of the holoscape display in Jurassic World show an image of a Dilophosaurus that is a plain light woody brown color over its whole body, while a diorama at Benjamin Lockwood’s estate shows a solid green dilophosaur with a bright red cowl and crests. No living dilophosaurs have been seen with either of these two color variants, but it is not unreasonable to assume that some exist or existed with these.
Four-foot tall juvenile Dilophosaurus have been observed in the flesh, while digital renditions of adults have been seen. A hologram of an adult dilophosaur in the Samsung Innovation Center shows an animal that, while approximately twenty feet in length, has essentially the same proportions as the juveniles.
Hatchlings have never been observed in the film-canon, but one is depicted in the mobile game Jurassic Park: Builder. It has similar proportions to the adult, but the head is proportionally larger and the crests smaller. The cowl does not develop until adolescence. It is not known if the film canon proper includes this same development procedure for the cowl.
The growth rate of Dilophosaurus is something of a mystery. While InGen documentation does demonstrate that the animal should reach its full twenty-foot length, numerous sources associated with the original film claim that the juvenile size is as large as it gets. This includes Dr. Laura Sorkin’s notes, wherein she claims that Dr. Henry Wu’s genetic engineering is likely the reason for their small size. However, within the same canon source as Dr. Sorkin’s journals, the Tour The Island site includes a video which shows the full size of the dilophosaur as twenty feet and states that those in the Park are currently juveniles. The reason for this internal discrepancy is not known, and it has been suggested that the dilophosaurs did not grow as rapidly as they were expected to. The Department of Prehistoric Wildlife states that Dilophosaurus grows only to 2.7 meters in length and 1.5 meters tall, the proportions of a juvenile.
While no sexual dimorphism has been observed directly, it is mentioned in concept art for the films; the male appears to be larger, more brightly colored, and with taller crests and a larger cowl.
Jurassic Park: The Game implies that genetically modified Dilophosaurus cloned by InGen may be capable of protogyny. As of such, an animal which outwardly appears female may actually have male reproductive organs, assuming that the eggs witnessed in the game were fertilized and that this animal’s genome does contain Hyperolius viridiflavus DNA. If these eggs were unfertilized and the genome contains only Dendrobates leucomelas DNA, it is incapable of protogyny.
Dilophosaurus appears to prefer wet, warm forested habitat. It has been sighted in heavily forested areas, and all three of its known paddocks in the original Park include large amounts of trees, shrubs, and undergrowth. They may nest in such regions, and are known to venture into upland areas. Their territories are marked with acrid-smelling pheromones and often contain the carcasses of numerous small animals. Venom splattered on trees, the ground, and foliage is another common telltale sign of dilophosaur activity, but it is unknown whether this is a territorial marking behavior.
Fossil evidence suggests that they prefer to remain near sources of water. The mobile application Jurassic World Facts states the same, implying that the cloned dilophosaurs may have similar habitat preferences to their fossil ancestors. It was the first animal introduced to a swamp biome in Mantah Corp’s testing facility in June 2016, and they took readily to the soggy environment. Thick plant life and mist enable them to ambush prey easily, and muddy ground helps to keep their footfalls quiet.
These animals are nomadic, and therefore can adapt to multiple kinds of environment. They travel along with their food sources. In more recent times, this dinosaur has been known to adapt quite well to areas that have been disturbed by human activity, using artificial structures for shelter the same way it might use trees and caves in the wild.
InGen cloned Dilophosaurus on Isla Sorna sometime following September 20, 1991, at which point Dr. Wu was still perfecting the genome. It is not known where on Isla Sorna the dilophosaurs lived, though John Hammond later asserted that the carnivores chiefly kept to the island’s interior regions. As this animal preys upon fish and other small animals, it probably kept somewhat near Isla Sorna’s many tidal inlets and rivers.
At the last count before InGen stopped monitoring Isla Sorna in 1993, there were twelve Dilophosaurus confirmed living on the island. None were encountered in 1997, though audio recordings kept by John Hammond (found on the InGen IntraNet website) give clear sound of this dinosaur living in the same habitat as Brachiosaurus. This places them in the western region of the island.
Animal territories were shuffled around after the 1997 incident, and also in the last years of the 1990s into the early 2000s as new creatures were illegally bred there. As nomadic creatures, the Dilophosaurus would not have been as heavily impacted by the effects on the ecosystem, but trouble did eventually come for all of Isla Sorna. By 2004, the island had suffered a catastrophic population crash. The decrease in population was also impacted by poaching. Beginning in September 2004 at the earliest, InGen under the wing of Masrani Global Corporation began removing the surviving animals from Isla Sorna and delivering them to Isla Nublar, where they remained.
According to Masrani Global, no de-extinct animals live on Isla Sorna today, but the Department of Prehistoric Wildlife acknowledges the possibility that some might still exist there. As a hardy survivor able to capitalize on many types of food, the Dilophosaurus could theoretically still be alive, or may have possibly spread to other parts of the Muertes Archipelago.
Three dilophosaur paddocks existed in the original Jurassic Park on Isla Nublar. The primary paddock, located to the west of the paddock areas, is the only one confirmed to house any dilophosaurs prior to the incident. As this species was cloned between 1991 and 1993, all animals were juveniles at the time. The primary paddock included a reasonably sized stream as well as dense forest, and bordered the main tour road to the northeast separated by a five-foot electric fence. To the southwest, it bordered a service road, also separated by a five-foot electric fence. To the west, it bordered the perimeter fence, and to the south, it bordered a twenty-four-foot-tall electric fence that separated it from what would have eventually become the Proceratosaurus paddock.
The secondary dilophosaur paddock was located farther north, near the central mountains of the island. It bordered the main tour road to the northwest, separated from it by a five-foot electric fence and also heavily forested. On all its other boundaries, it was separated from other animal paddocks by the twenty-four-foot electric fence; to the east was the primary Triceratops paddock, and to the south was the primary herbivore paddock containing both Brachiosaurus and Parasaurolophus. No animals are known to have been housed here, though plans were presumably in place.
The tertiary dilophosaur paddock was located much farther east. While there was signage on the roads leading to the paddock to warn employees and visitors of the animal, none are confirmed to have been housed there at the time of the incident. This paddock was likely similar to the others in terms of ecology. It was separated from what would have been the Baryonyx paddock by the main tour road, with a five-foot-tall electric fence on the dilophosaurs’ side. The tour road was present on the eastern and southern sides of this paddock. On its other borders, the twenty-four-foot paddock fences separated it from the tyrannosaur paddock to the north and the original Velociraptor paddock (later intended to be the Herrerasaurus paddock) to the west. It has been suggested that, due to the rapidity with which dilophosaurs appeared in this area during the incident, that some were already present here, but there is no direct evidence to support this claim.
All of the dilophosaurs on Isla Nublar as of 1993 were assumed to be females, but the presence of eggs found during the incident suggests that at least one may have become a male.
On June 11, 1993, the Park’s power grid was sabotaged by a disgruntled employee, permitting the animals to leave their paddocks. Within minutes, one of the juvenile Dilophosaurus was present near the East Dock, someplace south of the tertiary paddock. A broken egg, presumed to belong to a dilophosaur, was found in the immediate vicinity. Some minutes after that, a group of five dilophosaurs including the original was present in that area; one was killed when it was struck by a vehicle, and the remainder fled when driven away by Troodons.
A sixth dilophosaur was observed nesting between the Western Ridge and Bone Shaker on June 12. Its nest contained four eggs, one of which was unintentionally destroyed by the rescue operation taking place on the island. Footprints potentially belonging to Dilophosaurus were found in the Western Ridge, but they differ in morphology from known dilophosaur prints. These may have instead belonged to Herrerasaurus, which had a similar range at the time.
In October 1994, InGen surveyed the island to assess the animal populations. The five remaining Dilophosaurus were found to still be alive and had remained as a cohesive unit; the lack of any new animals indicates that their eggs did not survive. They did not settle in any particular location and appeared to be nomadic, roaming around the island.
Dilophosaurus survived in the wild on the island until InGen returned to reclaim it in 2002. It is possible that some dilophosaurs may have been shipped to Isla Sorna during construction; however, according to Simon Masrani, there were dilophosaurs living in contained areas of the island as of August 2004. Because very few dinosaurs had yet been returned to the island, and no carnivores had been shipped over yet, this means that at least some dilophosaurs remained on Isla Nublar during the entire construction period. They likely remained in the north of the island.
Throughout the final months of Jurassic World‘s construction, beginning after September 2004 and ending sometime before the park’s opening date at the end of May 2005, the remaining Dilophosaurus from Isla Sorna were shipped to Isla Nublar. Following a period of isolation in the quarantine paddocks, they would have been integrated into habitats in Sector 5. They most likely remained there for the ten-year duration of Jurassic World’s operation.
No dilophosaurs are known to have been exhibited in Jurassic World. However, the aluminum oxynitride glass of the gyrospheres was specifically said to be a defensive measure against Dilophosaurus, which suggests that the animals escaped captivity and entered the central valley frequently enough to merit mentioning to visitors in the safety video. Alternatively, dilophosaurs may have been exhibited at some point in the past and were removed for safety concerns or other reasons.
According to Jurassic World: Evolution, the tyrannosaur was the only animal from the original Park still on the island by the time of the 2015 incident. While this contradicts statements made by film director J.A. Bayona, it would imply that none of the original dilophosaurs were still alive by that time.
Following the island’s abandonment after December 22, 2015, the dilophosaurs would have been able to roam freely over the island. It is unknown how many existed on the island for this period of time. At an unknown day in June 2016, at least one dilophosaur was heard near Main Street, suggesting that some lived in that area. An image released by the Dinosaur Protection Group on February 4, 2018 confirmed that Dilophosaurus still lived on the island at that time; they were encountered during the night of February 17 by operatives on Isla Nublar, with at least three juveniles being confirmed in the bowels of the NMS Centre’s geothermal plant. One of these animals had the standard yellow-orange cowl color, while one had a green-shaded cowl and another had a magenta-shaded cowl. The dilophosaurs were exhibiting nesting behavior within the plant, using the ventilation shafts to reach the surface at night. This helped them avoid competition and attacks from Velociraptor, which lived in the upper sections of the Centre; the raptors were known to have struggled to navigate within ventilation shafts while the dilophosaurs excelled at it.
On June 23, 2018, Mount Sibo erupted violently and caused massive ecological and physical damage to Isla Nublar. Any Dilophosaurus surviving after the eruption would have suffered a loss of food sources and forest habitat, potentially leading to their extinction. A deleted scene for the film would have shown that at least two dilophosaurs were removed from Isla Nublar by means of the S.S. Arcadia.
Mantah Corp Island
In June 2016, four young Dilophosaurus were introduced into a Mantah Corporation testing facility on a small island to the east of Isla Nublar. They were held in the recently-constructed tropical swamp biome, the fifth habitat built in the facility; despite the extensive security measures in place, there were concerns about controlling their spirited escape attempts. It is unknown whether these animals were cloned by Mantah Corp, or poached live from an InGen facility.
One of the animals was consumed by a Nothosaurus shortly after being introduced, reducing the population to three.
BioSyn Genetics Sanctuary
After the release of numerous de-extinct animals into the wild, and the open-source release of de-extinction technology, creatures such as Dilophosaurus became problematic in inhabited areas. Some countries, eager to have their problem quickly and cleanly dealt with, contracted BioSyn Genetics to work alongside the Department of Prehistoric Wildlife to capture and contain certain animals. Among these was Dilophosaurus, a species that was likely of great concern to people due to its dangerous nature. Captured dilophosaurs were transported to facilities such as the BioSyn Genetics Sanctuary, located at the company headquarters in BioSyn Valley of the Dolomite Mountains.
As of early 2022, there were at least three young adult Dilophosaurus living in the valley. They were commonly sighted in the wooded areas where they preyed on deer and other small animals, sometimes investigating artificial structures such as the valley’s research and monitoring stations. They also sometimes ventured underground; their naturally exploratory natures could drive them into tunnels built by humans. When the BioSyn Hyperloop was shut down in early 2022 during an emergency incident, three Dilophosaurus entered the train tunnels and broke into a Hyperloop pod. They were not normally allowed here, with their neural implants restricting them to the valley proper, but during the incident a wildfire forced BioSyn to herd its dinosaurs underground to the emergency containment area. This is likely how the dilophosaurs accidentally ended up in the Hyperloop system. After the incident, the United Nations took over operation of the valley and presumably ousted the dinosaurs from the tunnel.
This is one of several species which has been poached from InGen facilities, either as DNA samples, eggs, or live specimens. While the most notorious poachers were Mantah Corporation (as discussed above), it is likely that others have also attempted to capture this dinosaur, though success at holding it has probably been less common. Dilophosaurus is not just dangerous, but a crafty escape artist able to challenge most security measures. Sightings of wild dilophosaurs may indicate animal trafficking in the area.
Such a dangerous animal capable of producing medically-significant venom would probably fetch a high price. It is believed that at least two (as per deleted scenes from Jurassic World: Fallen Kingdom) were removed from Isla Nublar by Ken Wheatley and mercenary crew on June 23, 2018 and either sold or released into the wild from the Lockwood estate the following day; their exact fate is not known. DNA from this species entered the black market at that time as well. More Dilophosaurus have been cloned now that the technology to create them has gone open-source. Black market locations such as the infamous Amber Clave in Malta may risk bringing this species through their doors for the right price.
Dilophosaurus was one of the first carnivorous dinosaurs to grow to a reasonably large size, existing about 193 million years ago in the early Jurassic period. It inhabited the western part of Laurasia, the northern continent created by the breakup of Pangaea during the beginning of the Mesozoic. Its habitat featured sluggish rivers and encroaching sand dunes, with distinct wet and dry seasons. To tolerate weather extremes throughout the year, Dilophosaurus was a very hardy animal, but it still eventually became extinct as its world changed. Fossilized remains were later used to reconstruct its genome and clone it in the late twentieth century, but the genetic engineering processes used altered the dinosaur almost beyond recognition.
In the predawn hours of June 24, 2018, one or two of these recreated dilophosaurs may have been released from captivity near Orick, California. If one or both were not released, they may instead have been sold on the black market. Their precise fate is not known, but from these two and the DNA samples taken off Isla Nublar, a new generation was born. Tenacious nomadic hunters and never keen on captivity, Dilophosaurus escapees can easily disappear. While not completely impossible to track and trap, these elusive animals are quick to vanish into uninhabited woodland, never to be seen again.
Behavior and Ecology
Dilophosaurus is nocturnal, meaning it is predominantly active at night. They may also be seen at dusk, though this is less common.
Diet and Feeding Behavior
A carnivore, Dilophosaurus feeds predominantly on fish and small dinosaurs, which it captures by ambush. It then uses its strong legs and grasping hands to grapple with prey items and force them into submission. It does not generally use its jaws to kill prey; its teeth are narrower than those of later theropods, and its frame more lightweight. Still, even a juvenile dilophosaur can use its strength and agility to take down human-sized prey with great efficiency. They are bold, sizing up potential prey with clear signs of curiosity.
The feature that makes Dilophosaurus such an efficient predator is its venom. While venom is common in reptiles such as snakes, it is fairly rare in dinosaurs, and Dilophosaurus is the only one known to spit its venom. It uses both sight and smell to locate prey, and once it has accurately gauged its prey’s location, the animal will forcibly expel a fairly large quantity of thick, sticky venom at its target. It will typically aim for the eyes. The venom can cause severe damage to the eyes of the victim, potentially leading to blindness and thus disorientation. If left alone, the venom can lead to full-body paralysis. Once a prey item is hit, the dilophosaur will often wait for the venom to take effect before moving in for the kill. Prey may be eaten alive once paralysis sets in, or left for later. Small animal carcasses are a common sight in dilophosaur territory, often all kept within a relatively small radius so that the dinosaur can easily access them.
While a solitary dilophosaur is a formidable predator in its own right, these animals are at their most fearsome when operating in groups. The hunting group’s leader will mark the prey item with its venomous expulsion, which disorients the prey. Communicating using both visual and vocal cues, the group will then corral the prey, attempting to corner it someplace where it is vulnerable. While the alpha is the one which initiates the attack by spitting venom, any of the dilophosaurs may use their venom to incapacitate the prey. The neck cowl may also be brought into play, being used to surprise and frighten the victim into making a misstep. Dilophosaur packs have even been known to target small groups of prey, splitting into teams to take down two prey items simultaneously. These modestly intelligent carnivores are able to strategize efficiently and are tenacious hunters, rarely giving up the chase until they manage to make a kill.
In the game Jurassic Park: Operation Genesis, the favored prey of Dilophosaurus is said to be the ornithopod Dryosaurus; however, this animal has not been cloned by InGen in the film canon. Its diet likely included the Nublar tufted deer and feral goats, as well as small dinosaurs such as Microceratus and Compsognathus; all of these animals are known to live in similar habitats.
Most Dilophosaurus are social animals, preferring to live in small groups called herds or packs. These groups have defined hierarchies and family-like structure. A leader or “alpha” is in charge of hunting, and is the one to initiate an attack by spitting venom at the intended prey item. The others follow the alpha’s lead. These animals are highly vocal with one another and have a complex communication system; they also use their cowls and crests to display and signal to members of their own species, with some amount of individualism occurring. While the original clones were visually and genetically identical to others of the same version number, their descendants are more individualistic, as befitting a naturally-social species.
Along with vocalizations, Dilophosaurus uses scent to communicate. Groups will mark the boundaries of their temporary territories using pheromones which give off a distinctive sharp, sour smell. Since they are nomadic, these markers will eventually fade after they leave the area. Venom is often seen splattered on objects in their territories, but it is unknown if these serve any visual signal.
The InGen IntraNet website describes dilophosaurs as having a sophisticated social life, with apparent rules and manners surrounding resting, breeding, and hunting. However, there are some individuals that prefer a solitary life and travel alone. Since this dinosaur is reclusive and seldom seen, its social behaviors are not yet fully understood.
All dinosaurs lay eggs to reproduce, and the dilophosaur is no different. Courtship displays involve the use of the cowl, as well as the head crests; these are the dilophosaur’s most noticeable features, and the only parts of its body not designed for camouflage. Scrapped concepts for the first film suggest that the male’s size and brightness of cowl color are factors in determining whether a female will mate with him.
While it is unconfirmed, some fans have suggested that the yellow hooded raincoat worn by Dennis Nedry during the 1993 incident resembled a male dilophosaur’s cowl closely enough to attract the attention of a female. If true, this would be in line with the idea that the cowl is used in mating displays by the male.
Dilophosaurus reaches sexual maturity long before it reaches skeletal maturity, so it is able to breed when it is much less than full-sized. During the 1993 incident, eggs were found to have been laid by dilophosaurs that were around five feet long, or a quarter of their maximum size. Both the male and female have a cloaca, which houses the sex organs.
The nests are scraped together using earth and other debris, but the eggs are left uncovered; this suggests that the adult broods them like a bird. The eggs are round and somewhat large, a few inches in diameter, and are white and gray. A juvenile mother dilophosaur may lay around four eggs in a clutch and guard them fiercely. However, the remainder of the social group may leave her alone to hunt some miles from the nesting site; this may be to avoid drawing attention to the nest’s location. Dilophosaur parents have been known to abandon their eggs if a great enough threat is present. Presumably, the full-sized adult would be capable of laying more eggs than the juvenile owing to being larger.
Smaller theropods usually have incubation periods lasting between three and six months, and the dilophosaur being on the lower end of the size scale means that it would likely have a shorter incubation period. They are ferociously defensive of their nesting sites, regardless of whether eggs have been laid yet. It is unknown how long the parents care for their offspring; adolescents are capable of fending for themselves, so they do not need parental care to survive at this stage.
Among the theropods, perhaps only Velociraptor is known to have a more diverse and complex system of communication than Dilophosaurus. This animal produces a wide variety of cries that have been compared to monkeys, birds, and other creatures; it possesses a surprisingly advanced syrinx, similar to that of the modern whooping crane (Grus americana). If the original Dilophosaurus had this organ (and not just the genetically-engineered version), then the modern bird syrinx could be considered an example of convergent evolution with that of earlier theropods.
Because relatively little observation into Dilophosaurus social life has been described or shown, their vocalizations are still not entirely understood. However, the general meanings of many of the sounds they make are fairly clear. When confronting an unfamiliar animal, a dilophosaur can be heard making trilling and chirping sounds; these have been interpreted as indicating uncertainty, curiosity, or sociability. Hooting sounds are almost universally indicative of arousal or anticipation and are often followed by more aggressive behavior. These hooting sounds can easily be mistaken by a human to indicate friendliness, but are actually signs of mounting excitement in the animal. More rapid hooting and chirping can be heard from an angry individual; the rapidity and frequency of the vocalizations appears to distinguish between anticipation and anger.
During hunts and other aggressive behaviors, the animal can be heard growling, snarling, and hissing; some of these sounds serve to frighten the prey into movement, but they presumably also serve to communicate among the pack when multiple dilophosaurs hunt together. For example, a very specific hissing sound immediately precedes a venom-spitting attack, which would allow one dilophosaur to alert its packmates to its impending action. When the cowl is extended, it can be shaken to produce a rattling sound, which draws attention to the animal. This cowl-rattling may be used for signalling or intimidation.
Dilophosaurus also uses visual cues to communicate. The cowl is the most obvious example; it is used to intimidate rivals, signal to potential mates, and engage in other social behaviors. During pack hunts, Dilophosaurus will frequently flare its cowl when confronting prey. This often causes the prey to freeze in surprise or change course. When one dilophosaur flares its cowl at a running prey item, it not only signals to its fellows where the prey is, but also attempts to redirect the prey. Dilophosaurs likely pay attention to the flaring behavior of their hunting partners as a means of communicating how best to corral and incapacitate the prey. The venom often splatters on trees, foliage, and other objects; it is unknown whether this could be used to communicate between groups of dilophosaurs. Pheromones, which have a sharp sour smell, are used to mark territorial boundaries.
In addition to communicating with one another, the aggressive displays of Dilophosaurus also can be used for interspecific communication. For example, the cowl is flared at competitors and predators when the dilophosaur is confronted. This can be seen as a kind of honest signalling, indicating to the predator that the dilophosaur is healthy and able to fight back. By shaking its cowl to produce a rattling sound, as well as hissing, the dilophosaur can advertise its status as a threat to animals nearby and discourage them from preying on it. These techniques are also used on prey; the sudden appearance of a colorful cowl and surprising noise will often cause the prey to look directly at the dilophosaur, giving it an easy shot at the prey’s eyes. From here, the dilophosaur will continue to use visual and vocal displays to confuse and disorient prey, causing the prey to stumble and fall while it attempts to flee. The dilophosaur can then easily wait in ambush for the prey to blunder into a vulnerable state.
Jurassic World: Evolution includes most of these vocalizations and visual displays in the animal, and also gives it more social behaviors. When socializing, the dilophosaurs will make cawing and rasping sounds, and briefly extend and then retract its cowl.
The Dilophosaurus is one of InGen’s most successful predators, owing to its multiple adaptations (both naturally-occurring and as a result of gene splicing). It is mostly a small-game hunter, but is adept at efficiently killing prey while also avoiding predators. Between the 1993 incident and 1994 island assessment, Dilophosaurus was one of only two dinosaurs whose population was not found to have decreased. The other was Tyrannosaurus, which had a population of one animal.
It is known to prey on fish and small dinosaurs. Compsognathus are known to inhabit the same territory as Dilophosaurus; compy footprints were sighted around a dilophosaur nest during the 1993 incident, though it is not known if the compies were actively attempting to prey on the eggs. Herrerasaurus inhabited a nearby area, and Tyrannosaurus and Pteranodon were likewise sighted nearby. In particular, the huge territories claimed by Tyrannosaurus would mean that a group of dilophosaurs might migrate over some considerable distance and still remain within a tyrannosaur’s territory. Modern animals, including birds such as the collared aracari (Pteroglossus torquatus) and Franklin’s gull (Leucophaeus pipixcan), are known to have inhabited the same territory as Dilophosaurus and would have been potential prey items, and following the 2015 incident, the small dinosaur Microceratus is also known to have occurred in dilophosaur territories and was most likely eaten by them.
Because of their preference for water and diet including fish, there is a good chance this small theropod would have competed with spinosaurs such as Baryonyx, Suchomimus, and Spinosaurus for space and food. Here, its venom would give it an advantage over these much larger and brawnier piscivores. Pterosaurs such as Pteranodon and Dimorphodon would also be potential competitors, as would the water-loving Ceratosaurus. The aforementioned pterosaurs were found near the Jurassic World Lagoon between late 2015 and the summer of 2018, an area that dilophosaurs were known to inhabit as of 2016. Ceratosaurus, on the other hand, is known to have moved into the central region of the island at the end of 2015.
On Isla Nublar, Dilophosaurus was known to venture into the central valley, which was home to a great number of considerably larger animals. These would be vastly outside of a dilophosaur’s prey range, excepting perhaps Gallimimus and Pachycephalosaurus; it is more likely that the forest-loving and reclusive Dilophosaurus would avoid the open plains where the huge herbivores roamed. During its time in the wild on Isla Nublar during the 2015-2018 period, it probably encountered large herbivores including Parasaurolophus, Sinoceratops, Brachiosaurus, Triceratops, Stegosaurus, Ankylosaurus, Edmontosaurus, Apatosaurus, and Peloroplites, as well as the smaller herbivores mentioned above. Many of these other animals were too large or well-defended to be worth the risk of attacking, but it could easily prey on juveniles, scavenge carrion, or prey on weak or sick individuals.
Benjamin Lockwood’s estate includes a diorama depicting a confrontation between two juvenile D. venenifer and an adult female Velociraptor antirrhopus nublarensis, but no confrontations between these species have been recorded. In one instance, Dilophosaurus succeeded in nesting directly underneath Velociraptor territory by making their home in the geothermal power plant of the North Mount Sibo Centre, accessing it via ventilation shafts that the raptors could not use. The plant was otherwise sealed off from the rest of the Centre until early 2018. This ensured that the two species could avoid one another. While they are tenacious predators and fiercely defensive of their nests, Dilophosaurus will back down from Troodon pectinodon. They avoid confrontation with this species and give it a wide berth, as most animals do.
It is not without parasites and pests. The folds of its cowl provide ample surface area for microorganisms to grow on, and if not kept clean and dry, the cowl could become infected with parasitic fungi. A dilophosaur with a fungal infection in its cowl would have a hard time hiding this health defect from its peers, and as the cowl is essential in the mating display, it would be unlikely to attract a mate in such a condition. Like most de-extinct animals, its DNA was originally recovered from preserved parasites such as mosquitoes, confirming that these blood-sucking organisms once targeted Dilophosaurus. It is unknown if modern mosquitoes feed upon it like their ancestors did.
In Jurassic World: Evolution, the Dilophosaurus is uncomfortable with large populations of other species near itself and prefers to live among its own kind. It is particularly susceptible to parasitic hookworm infections.
While the original animal, Dilophosaurus wetherilli, is mostly known to paleontologists, the de-extinct Dilophosaurus venenifer has become widely known among dinosaur enthusiasts for its unique features not seen in other species. Few known dinosaurs are venomous, and no others have cowls. The only other animal known to have a similar structure is the frill-necked lizard (Chlamydosaurus kingii). Since the creation of Dilophosaurus venenifer and its reveal to the general public, it has often been confused with the small Australian reptile, with some people mistakenly thinking that the lizard is actually a small Dilophosaurus or that it spits venom. The two animals are actually not close relatives and, aside from having similar neck frills, do not even really resemble one another.
Although its venom glands and cowl are probably unintended results of gene splicing, the general public has largely assumed InGen’s dilophosaur to be an accurate representation of the original animal. No amount of education seems capable of dispelling this misconception, so depictions of Dilophosaurus in video games or other media almost invariably give it at least one of these new features. Perhaps because of this, it has become notorious among paleontologists as one of several widely-misrepresented dinosaurs, and is symbolic in general of the public’s poor understanding of actual paleontology. It is a common feature in paleoart, especially among artists who hope the public will notice their rendering based on fossils rather than InGen’s animal.
Besides summing up the state of laypeople’s dinosaur knowledge, Dilophosaurus is sometimes seen as emblematic of the genetic engineering shortcuts taken by InGen’s Dr. Henry Wu by his detractors. It shares this role with Velociraptor, another dinosaur exhibiting an unusually large number of altered physiological features.
Dilophosaurus is the state dinosaur of the U.S. state of Connecticut. The species Dilophosaurus wetherilli was proposed as state dinosaur for Arizona, but its candidacy was vetoed when it was revealed that the fossils in question had been illegally taken from Navajo Nation land.
Dilophosaurus was intended to be exhibited in Jurassic Park, with three separate locations where it would be visible along the main tour road. Guests were to be advised to keep their windows rolled up while passing through these areas, though; employees likewise would have to wear eye protection when working with Dilophosaurus. In spite of this, John Hammond was clearly pleased with how this species had turned out and placed it first on the Jurassic Park tour. Its seemingly playful curious behavior would theoretically make it appealing, even if its curiosity was almost always a sign that it was looking for food.
In actual practice, Dilophosaurus made a poor Park attraction due to its nocturnal nature and cryptic coloration. It did not make an appearance when the endorsement tour occurred, though they did escape confinement in the ensuing incident. Two deaths have been attributed to Dilophosaurus as a result of the incident. However, this animal is fairly elusive and rarely encountered.
Perhaps due to lessons learned during the original Park’s operation, it does not appear that attempts were made to exhibit this animal in Jurassic World at any point. It did sometimes escape its habitat in Sector 5, escaping into Gyrosphere Valley where it could encounter guests. Dilophosaurus has nowhere near the strength needed to break into a gyrosphere, but nonetheless, guests were reassured in the gyrosphere safety video that Dilophosaurus venom could not penetrate the aluminum oxynitride glass. Dilophosaurus was also featured on the holoscape in the Innovation Center.
Another attempt to hold Dilophosaurus in captivity was undertaken by Mantah Corp in June 2016. While it is not known how or from where they obtained their specimens (from Isla Nublar or Isla Sorna, captured alive or bred from stolen genetic samples), the four juveniles were introduced to a swamp biome constructed in a clandestine facility. This was despite concerns from the facility administrator, Kash D. Langford, that the animals were uncontrollable; no doubt he had heard stories about their escape efforts in Jurassic World over the years. Their purpose in the Mantah facility was to be tested for entertainment; their unique appearance and venom would make them popular. To keep them captive, the facility utilized advanced security technologies including invisible fences projected from quadcopter drones and Mantah’s state-of-the-art biomimetic robots.
While the original Dilophosaurus has provided paleontologists with valuable and informative fossil specimens, the engineered version created by InGen is not as paleontologically significant. This is because it exhibits enough physiological differences from the original to render it useless in the study of real prehistoric dinosaurs. However, as with most aspects of InGen’s bioengineering efforts, the real purpose of Dilophosaurus was never to study extinct ecosystems; it has yielded far more interesting information about genetics.
When Dr. Henry Wu created this animal, it showed marked deviations from what was expected. The presence of venom glands and an extendable cowl were completely unexpected, and largely unprecedented among dinosaurs. Prior to 1991, Dr. Wu had utilized genes from the yellow-banded poison dart frog (Dendrobates leucomelas) to replace decayed genes in the ancient DNA samples; it was these genes which resulted in the abnormal features developing.
However, this was not a simple case of functional genes leading to the development of anatomical structures. Poison dart frogs do not produce their own toxins; they obtain them in their diet of insects, largely rover ants. As of such, they do not have venom glands. Furthermore, no frogs are known to possess extendable neck frills. This means that the replacement genes did not, on their own, cause these features to develop. What happened here was potentially analogous to a frameshift mutation, in which a nucleotide is added or removed from the genome to alter how other genes are expressed. Rather than reading out as intended, the entire genome was shifted slightly, causing it to express entirely new traits. In many cases, such a mutation is fatal. In Dilophosaurus, it produced an exceedingly rare example of a beneficial frameshift mutation. The resultant animal functioned perfectly well. How this genetic modification achieved these unintended results is still unknown.
Later dilophosaurs may have been engineered using genes from the common reed frog (Hyperolius viridiflavus), rather than the yellow-banded poison dart frog, as filler. However, they were outwardly indistinguishable from other versions. If the switch was really made, it confirms that the source of the filler DNA was not in and of itself the cause of the alterations. This “happy accident” has major implications for genetic engineering: it means that, even if the roles of certain genes are completely understood, they may still have unintended consequences if their interactions with the host genome do not go as planned.
Dilophosaurus has had little contact with the general public and so is not often involved in politics. It was a known security risk in Jurassic World, as the dinosaurs would sometimes breach containment and venture into Gyrosphere Valley, but no major incidents are confirmed. It did not become a major political issue until 2017, when volcanic activity threatened to destroy Isla Nublar’s artificial ecosystem and render its inhabitants extinct. As a predator that could threaten a human, the survival of Dilophosaurus was considered especially contentious, and some suggested letting it go extinct on purpose. This was opposed by the Dinosaur Protection Group, though this species in particular did not feature in very much of their material.
The U.S. Congress ruled on June 22, 2018 that no action should be taken to salvage Isla Nublar’s animal life, on the grounds that the island was on lease from Costa Rica by Masrani Global Corporation and thus outside U.S. jurisdiction. An illegal capture operation was conducted instead by the Lockwood Foundation, though rather than relocate the dinosaurs to the privately-owned Sanctuary Island, they were brought to the Lockwood estate to sell on the black market. It is currently believed that at least two Dilophosaurus were involved, but whether they were sold to an unknown party or released by activists along with the other animals is unknown.
While originally bred as a park animal, this dinosaur’s behavior patterns make it a poor performer since it likes to remain hidden and mostly comes out at night. Its colorful cowl would make it theoretically attractive, but a dinosaur visitors are unlikely to see will not draw crowds no matter how visually interesting it is. Jurassic World opted to leave it out, instead putting up displays of the animal for visitors to see. Benjamin Lockwood similarly had a model of a Dilophosaurus in his residence. The practical uses of this dinosaur are more scientific in nature; its unexpected anatomy yields possibilities for the field of genetics, and it possesses unique biopharmaceutical properties. Venom is often used in medical research, and the unconventional origin of dilophosaur venom makes it especially interesting.
The potential applications of Dilophosaurus and its venomous spit did not go unnoticed by people seeking to exploit them. Mantah Corp, a rival to InGen and Masrani Global, illegally obtained this dinosaur and began housing it in June 2016; the purpose of this was to put it in combat for the entertainment of the extremely wealthy. Efforts were made to control their behavior through the use of medication, drone technology, and brain implants. In 2018, at least two Dilophosaurus may have been collected by Ken Wheatley at the behest of Eli Mills; it is unknown if any were successfully brought to auction, and if so, what became of them. Selling these dinosaurs was meant to finance Henry Wu’s continued research; Mills expected each specimen to sell for millions of dollars. At least its DNA was successfully sold among at least eleven other specimens to a Russian buyer, probably the gangster Anton Orlov.
Although it rarely encounters humans, Dilophosaurus is a highly efficient predator and is hard to discourage once it targets a prey item. To avoid running into this dinosaur, avoid the conditions in which it hunts: dilophosaurs prefer woodland, the denser the better, and are most active from dusk to dawn. Dark conditions coupled with their natural camouflage helps them sneak up on prey, which they locate mainly through sense of smell. Their eyesight is good, but sniffing out food is easier than looking for it in the dark. If you must venture through their territory, do not bring food with you and try to hide your scent by any means you can. Flashlights are also invaluable defensive devices; since these dinosaurs are nocturnal, a sudden bright light can startle and scatter them. Be on the lookout for signs of activity, especially dried venom splattered in a paint-like fashion on objects or carrion. Numerous small animal carcasses within a limited radius are a sure sign that this dinosaur is living nearby, and a sharp sour scent indicates the boundary of their territories. Should you see the animal itself, do not turn your back on it. Instead, back away slowly while keeping your face shielded. Do not allow it to come within six meters of you, as it can strike accurately from such a distance.
Dilophosaurus attacks chiefly occur for two reasons: food, and defense of territory. If they are hunting for food and target you, they will probably set up an ambush, which may involve one or more animals. When defending yourself against a group, identify the alpha. It is the one that will fan out its cowl first, and then spit venom at you. The others will follow its lead, so if you can discourage it, the others will probably back down as well. Your first priority should be to protect your eyes. When the alpha fans its cowl, it is trying to get you to look directly at it. As much as your instincts will tell you to keep this obvious threat in your line of sight, it is a trick. The alpha will aim to spit in your eyes, blinding you and making you an easier target. You are safer if you wear glasses or other protective eyewear, but for people who don’t or can’t, protect your eyes using whatever else you can find. Even just shielding your face using a piece of clothing or your hand might save your life. If you do get venom in your eyes, immediately flush them out with water. Doing this quickly enough may reduce protein damage enough to prevent blindness. Protect your mouth as well to avoid ingesting the toxin.
However, the venom is only the first stage of attack. If you are hit and cannot prevent blindness, you need to get to defensible shelter immediately. Any sturdy building or vehicle is feasible, but you will want to be absolutely sure there are no other ways into your shelter; these animals are crafty and very good at navigating tight spaces. Passageways such as air vents or windows need to be blocked off. Try to set up as much defense as you can before the animals move in to attack. They will do so as soon as they think you are weak, so act confident. This will buy you some time.
When the attack does come, prepare for a physical fight. Though they are formidable, Dilophosaurus are lightweight compared to some other dinosaurs, and you may be able to hold your own against one. Strike it in the eyes, mouth, or nose with any weapon you can obtain, or just with your fists. They are tenacious but rather fragile and can be driven off from sufficiently strong prey. Fighting in a narrower space will force only one to face you at a time. Defend yourself against bites; while spitting is the initial attack, the venom is mixed with its saliva and could enter your body if its teeth pierce the skin.
Staying in groups is highly effective at fending off dilophosaur attacks, as they will pick off loners first. Weakness is easier to hide in numbers. If one of your group is hit, defend that person especially; they will need medical attention if they are to survive, so your job now is to prevent them from further injury. Blindness may be irreversible if the venom is not washed out of the eyes immediately, but they might still live. Driving away the dilophosaurs is a temporary solution until help arrives, since they will linger around and wait for their victim to become paralyzed. This will make the victim and your whole group more vulnerable, so it is best to try and escape while the dilophosaurs are biding their time. Just because they are out of sight does not mean you are safe yet; they are determined and willing to travel very far in search of food. Continue fleeing until you get to an inhabited area where they will be less likely to follow you.
If their attack is territorial in nature, rather than predatory, you are slightly better off. A territorial attack usually occurs if you intrude upon their nesting grounds, especially if they are breeding. Once you leave their territory, they will cease the chase. A territorial attack will not involve ambush. Instead, they will make clear deimatic displays, trying to startle or threaten you. Venom will still be employed in a defensive attack, so protect yourself the same way.
Once you have made it back to an inhabited area, immediately get medical treatment for any of your companions who have taken venom hits. Strikes to the eyes are the most dangerous, but the venom is neurotoxic and any skin contact should be cause for concern. It leads to paralysis if left untreated, which in the wild would be a death sentence. Humans, fortunately, have developed medicine, giving you an advantage over wild animals. Treatments for neurotoxins and hemotoxins are available and aid can be given to people who have been blinded or paralyzed.
Unfortunately, dilophosaur envenomation is such a rare occurrence that health insurances are likely to refuse to cover treatment. If you live in a country with underdeveloped healthcare such as the United States, prepare for a lengthy and very expensive recovery process.
Behind the Scenes
The unusual features of the film’s Dilophosaurus, including its extendable cowl and comparatively small size, were added to help viewers tell the difference between the Dilophosaurus and Velociraptor. Its venom is the only unusual feature that was originally a part of its depiction in the novel upon which the film is based; the idea of Dilophosaurus incapacitating its prey with venom is based on an older interpretation of its teeth being too fragile for biting.
In media associated with the first film, such as some of the trading cards, Dilophosaurus is said to only reach five or six feet in length. An exception to this is the Jurassic News magazine (1992), which in Volume 1 describes this dinosaur as being twenty feet long. The idea of it being a juvenile and reaching twenty feet as an adult caught hold in the franchise some years after the first film and has become standard now.
Despite attempts to explain the animal’s abnormal features through genetic engineering and growth stages, the general public (and a fair number of video game studios) have interpreted Jurassic Park‘s dilophosaur as an accurate representation, which it is not. Perhaps in an attempt to avoid criticism from the paleontological community, the filmmakers have avoided featuring the animal since the first film; it was planned to appear in 2018’s Jurassic World: Fallen Kingdom, but was ultimately cut, with any existing footage never to be released. The animal did not reappear in the film canon until the season finale of Jurassic World: Camp Cretaceous Season 4 in December 2021.
Juvenile Dilophosaurus – six individuals bred for Jurassic Park
Dilophosaurus “venenifer” (SF-Ride)
Dilophosaurus wetherilli “venenifer” (*) (JN)
Dilophosaurus “venenifer” (L/M)
Dilophosaurus wetherilli “venenifer” (*) (C/N)