Parasaurolophus walkeri (S/F) / (S/F-T/G)

Parasaurolophus, often called the parasaur, is a genus of large hadrosaurid dinosaur in the subfamily Lambeosaurinae. It belongs to the tribe Parasaurolophini, which gets its name from this dinosaur. Parasaurolophus originally lived during the Late Cretaceous period from 76.5 to 73 million years ago and inhabited western North America; at the time, that region was a subcontinent called Laramidia. The genus name Parasaurolophus means “near (or “similar to”) Saurolophus,” likening its appearance to a smaller genus of hadrosaur. The name of Saurolophus itself means “crested reptile,” so the name of Parasaurolophus can be translated as “near crested reptile.” There are three species known. The best known, Parasaurolophus walkeri, is identifiable by its mostly straight, slightly curved crest. Its species name honors Sir Byron Edmund Walker, Chairman of the Board of Trustees of the Royal Ontario Museum. The second species, Parasaurolophus tubicen, has a more complex internal structure to its crest, and the crest itself is straighter and longer; this species is larger in size, and has a species name meaning “trumpeter” in reference to the calls it would have made. The third and final species, Parasaurolophus cyrtocristatus, has a species name meaning “shortened-crested,” in reference to its comparably short, rounded crest. This third species is overall the smallest Parasaurolophus.

The first remains of Parasaurolophus walkeri, a skull and partial skeleton, were found in 1920 near Sand Creek in the Red Deer River of Alberta. This area is now a part of the Dinosaur Park Formation and dates to the Campanian epoch of the Cretaceous period. Researchers from the University of Toronto discovered the skeleton, which was missing most of its tail and the legs below the knees. In 1922, paleontologist William Parks named the genus and species. Few other remains of this animal have been found in Alberta, where it appears to have been rare.

Parasaurolophus walkeri bred for Jurassic World’s later stages. Some anatomical features suggest that it contains DNA sourced from Parasaurolophus tubicen.

Other remains were found in 1921 by Charles H. Sternberg in the Kirtland Formation of New Mexico; these rocks are about a million years more recent than those of the Dinosaur Park Formation.. The remains consisted of a partial skull; it was sent to Uppsala, Sweden where, in 1931, paleontologist Carl Wiman named the second species Parasaurolophus tubicen. Two more fossils of this species have been found, all within the De-Na-Zin Member of the Kirtland Formation.

The final species, Parasaurolophus cyrtocristatus, was discovered in New Mexico by John Ostrom in 1961. The fossil may have originated from the Kirtland Formation, though roughly a million years before P. tubicen would have inhabited the area, or from the underlying Fruitland Formation. More remains of this species were discovered in the Kaiparowits Formation of Utah. This smaller species was, because of its reduced crest size, thought to be a female or a juvenile of one of the other two Parasaurolophus species, but paleontologists by and large believe it to be its own species.

The Asian species Charonosaurus jiayensis is very similar to Parasaurolophus; a 2014 study suggested that it might actually be a fourth species of Parasaurolophus.

International Genetic Technologies has resurrected Parasaurolophus walkeri using ancient DNA recovered from Campanian amber samples. It was one of the first species to be cloned on Isla Sorna in the mid-to-late 1980s. As of June 11, 1993, InGen had created up to Version 3.01 of this species. The other two species of parasaur have not been confirmed in the film canon directly, but Parasaurolophus cyrtocristatus is present in the Jurassic World traveling exhibition, and the size for the animal on the Jurassic World website appears to be the maximum estimate for Parasaurolophus tubicen.

Description

This is among the larger hadrosaurs, reaching lengths of 25 to 31 feet (7.6 to 9.5 meters) and heights of 13 feet (4 meters) when standing upright. When on all fours, its height is closer to nine feet (2.7 meters). Specimens cloned for Jurassic World in the 2000s and 2010s are said to reach lengths of 40 feet, suggesting that P. tubicen DNA may have been sourced when genetically engineering new specimens of P. walkeri. The weight of this animal reaches 2.8 U.S. short tons (2,540.12 kilograms) in large animals, though most InGen specimens observed have been closer to 25 feet in length and so are probably lighter in weight. However, at least one adult specimen was measured at 3,560 kilograms (3.9 U.S. short tons) in 2018.

Visible internal anatomy of a dead Parasaurolophus. Featured are the digestive, muscular, and cardiopulmonary systems. Individual organs may be difficult to distinguish due to the animal being partially eaten.

A facultative quadruped, parasaurs are able to walk on two or four limbs as the situation requires. In general, they forage on all fours, but rear onto two legs when running. It has powerful legs and can run at a decent speed; this, along with social behavior, is its chief defense against predators. The feet have three hoof-like toes each, built for gripping the earth while running, while the hands have five digits. On the hands, four of the fingers are less distinct and bear only small claws. The fifth digit is the most distinct of the fingers. In the fossil ancestors of this animal, the four main digits were even less defined, fusing together into a single hoof-shaped hand while the fifth finger remained free and flexible. The forelimbs are short for hadrosaurs, though the upper arm is heavily built. Its pelvic bones and shoulder blades are also robust. Parasaurolophus is built for life on solid ground, rather than being semi-aquatic as scientists once assumed; it is a decent, but not excellent, swimmer, capable of holding its breath for short periods at a time and swimming in calm water while fully submerged. This dinosaur avoids strong currents and rough waters. It can jump from a bipedal stance, but not particularly high.

The skull of the parasaur is its most distinctive feature, easily standing out among other dinosaurs for its elongated and curved cranial crest. This structure is made up of a combination of the premaxilla and nasal bones, and contains hollow tubes. Each nostril connects to such a tube, which extends to the back of the crest before reversing direction and continuing down into the skull. These tubes were simplest in P. walkeri and most complex in P. tubicen, while the smaller P. cyrtocristatus had intermediate complexity in the tubes of its smaller, rounded crest. The skull of an InGen parasaur can reach five feet and three inches to six feet and seven inches long (1.6 to 2 meters) depending on the breed; the smaller size is comparable to fossil P. walkeri, while the larger size is more like that of P. tubicen. Also like P. tubicen, the larger parasaurs display longer and straighter crests, suggesting that InGen supplemented the genome of P. walkeri with DNA from its larger and later relative. The crest of this animal was suggested by paleontologists to function as a snorkel for breathing while underwater or as a weapon for intraspecific combat. Both of these hypotheses were rejected; the crest does not have a hole to be used as a snorkel, nor is it dense enough to be used in combat. Instead, it serves a social function, being used both as a visual display as well as an amplification chamber for the animal’s calls. The crest may also be used for thermoregulation, even facilitating the movement of cooler air to the brain.

The mouth of this animal is sheathed in a keratinous beak-like structure, which is toothless. Within the cheeks, it contains many small, densely-packed teeth; it is capable of chewing its food, making its digestion much more efficient. The tongue is small and rounded. Its eyes are somewhat large and round, with dark irises, yellow or orange sclerae, and round birdlike pupils. This dinosaur has good visual and auditory senses, befitting a creature that communicates extensively with display structures and complex vocalizations.

From the front, this animal strikes a relatively narrow profile, suitable for navigating between trees and dense foliage. It is not as thin as its relative Corythosaurus, but also not as thick as Edmontosaurus. Like many of the lambeosaurines, it has high neural spines, tallest over the hips; these create a distinct visible ridge down its back. The tail is not long, but somewhat deep, and overall not particularly remarkable.

Brown-colored female Parasaurolophus, Isla Sorna (11/2/1997)

This dinosaur has skin with tubercle-shaped scales. The base color is usually earthy green or brown, but is highly variable, ranging from a dull gray-green through bright yellow and orange. Most parasaurs show lateral stripes down either flank, originating around the sides of the head and extending to the hips or tail. These stripes are often darker than the rest of the body and border a lighter stripe in between. Some bear black-rimmed white stripes, while others have rusted red or earthy brown stripes. The underbelly is usually lighter in color, demonstrating countershading. Horizontal stripes may occur on the legs, adding gray or black color to the outer thighs. The ridge of the parasaur’s back is usually darker, similar to the stripes on its body; this is not universal, with some parasaurs lacking alternate color on their ridges. On the neck and crest, parasaurs may demonstrate a bright red color, though the bulk of the crest is usually darker. Crests vary in shading, with some featuring dark blue, dark purple, gray, or solid black; the upper snout and beak are typically the same color as the crest. The brightness of the body color may vary throughout the parasaur’s life, possibly due to hormonal changes. Some parasaurs bred for Jurassic World featured purplish-pink and white bioluminescence, which was present on the dorsal side of the cranial crest as well as the lateral stripes.

In Jurassic World, a new breed of parasaur was created, though it is unclear if any had reached adulthood by the time the park closed. This breed has some anatomical differences from its relatives, but its most striking difference is its color. It is usually a beige or tan color with heavy dirt-brown patterning, featuring stripes, splotches, and spots; the brown pattern becomes denser higher on the animal’s flanks and back until it becomes almost solid. The ridge is banded in brown and beige, as are the limbs. The head of this breed of parasaur features mint green striping on the upper face and crest, with the stripes running horizontally from the snout to the crest tip; the brown color appears in between the green stripes. The beak is a lighter tan color.

Growth
In the background is a juvenile Parasaurolophus, Isla Nublar (12/18/2015)

When this animal hatches, its crest is lower and hemispherical. It grows out into its adult shape as the animal begins to mature, with small juveniles having roughly the proportions of the adult. A juvenile can also be told apart by its proportionally larger skull compared to its body, as is the case in many animals. Fossil evidence has suggested that parasaurs reach adult size in about a year, much faster than other hadrosaurs, and begin developing their crests at an earlier age than their relatives. This is in line with what has been observed in InGen specimens; the crest becomes longer and tube-like while the animal is still rather small.

Sexual Dimorphism

Male and female parasaurs can be told apart by comparing their coloration. Males achieve brighter colors than their female counterparts, similar to many modern birds. However, sexing this animal is not always easy, because it exhibits high levels of individualism. A male parasaur with gray-green color, for example, cannot be as bright as a female with yellow or orange color. Identifying the sexes of a parasaur by color alone can only be accomplished by comparing individuals that have the same color scheme.

Habitat
Preferred Habitat
Social unit of female parasaurs, Isla Nublar (6/11/1993)

Parasaurs inhabit forested areas, where their food sources exist in abundance. They can tilt their heads back to retract the crest downward, making it easier to move through dense foliage. However, their hoof-like toes give them good purchase on most types of solid terrain, giving them excellent adaptability. These dinosaurs can live comfortably on grasslands and other plains regions, semi-arid climates, and even wetlands. Their ability to chew food allows them to feed on many different kinds of plants, which is part of the reason they are so adaptable. It is not adapted to a semi-aquatic lifestyle, though it prefers to keep near bodies of fresh water such as lakes and rivers.

Fossil evidence suggests that Parasaurolophus once inhabited coastal floodplains, riverbanks, and upland conifer forests, and lived during a time when temperatures were warmer and the wet and dry seasons were more extreme.

In the game Jurassic World: Evolution, the parasaur requires 7,600 square meters of forest and 5,200 square meters of grassland in its habitat to remain comfortable.

Isla Nublar

As early as 1988, InGen introduced Parasaurolophus to habitats on Isla Nublar where they were to be among the animals featured in Jurassic Park. This hadrosaur shared the herbivore paddocks with the sauropod Brachiosaurus. The primary herbivore paddock was located more to the north, featuring grassland in the west and dense forest to the east. It was bordered to the north by the secondary Dilophosaurus paddock, and to the east by the Tyrannosaurus and Velociraptor paddocks. To the southeast was the Gallimimus paddock. The animals were kept separate by twenty-four-foot electric fencing, and from the main tour road by a moat. In the southern herbivore paddock, grassland and sparse forest surrounded the Watering Hole, a large pond where the animals could bathe and drink. Its western border was defined by the Park’s perimeter fence, while the Jungle River marked its southern extent and the east and north were delineated by a service road. On the other side of the service road and a five-foot electric fence to the north was an empty paddock area eventually destined for Proceratosaurus. The road to the east simply separated it from an undeveloped area of land.

As of June 11, 1993, there were at least eight adult female and two juvenile female parasaurs present in the southern herbivore paddock; they were seen at the Watering Hole during the endorsement tour. These parasaurs could be identified by their green and blue color. In addition, there were four adult female parasaurs kept at Dr. Laura Sorkin‘s research paddock in the far northwestern region of the island, near Mount Sibo. Although they were explicitly said to be female, they possessed brighter orange and yellow colors with white stripes. One of these could be identified by a broken left toe, which made it exceptionally cautious. According to InGen documentation, there were fifteen parasaurs on the island after the 1993 incident, meaning that there was at least one more than those seen by the groups involved with those events. The footage for the Tour The Island site’s Compsognathus video implies that at least one parasaur on the island died prior to the 1993 incident.

Known (red) and possible (purple) paddock areas for P. walkeri on Isla Nublar prior to June 11, 1993

During the 1993 incident on Isla Nublar, Dr. Sorkin’s parasaurs were released from their paddock to allow them to survive until she could return to the island. The injured parasaur was hunted down and killed by a Velociraptor after being released on June 12; the others scattered from the paddock area. One was seen to the southwest of the paddock area. Over the course of the next year, the population was whittled down; the 1994 cleanup operation reported as of October 5 that, due to predation from Tyrannosaurus, only nine parasaurs remained.

Known (red) and speculative (purple) range of P. walkeri on Isla Nublar following June 13, 1993

When Isla Nublar was reclaimed in early 2002, the parasaur population was saved from further decline as InGen Security restrained the tyrannosaur in April and restricted the movements of other carnivores on the island. Between then and 2004, some parasaurs may have been shipped back and forth between Isla Nublar and Isla Sorna as InGen prepared for Jurassic World; as of August 2004, there were more than a dozen parasaurs living on Isla Nublar, all of which resided in the central valley. The parasaurs generally remained in the eastern half of the valley, opposite the Triceratops herd. Throughout 2004, any surviving parasaurs on Isla Sorna were rounded up by InGen and brought to Isla Nublar, where they stayed a short while in a quarantine pen before being introduced to the valley. Breeding resumed; along with the old stock, InGen bred a new variety of parasaur sometime by 2014. Since its image on the Jurassic World website was an illustration rather than a 3D render, it is believed that none of these new parasaurs had reached maturity by late 2015. None have ever been seen, so it is possible that they have died out. While breeding occurred in the park between 2004 and 2015, young parasaurs would be bred in the Hammond Creation Laboratory before spending their juvenile stage in the Gentle Giants Petting Zoo.

Range of P. walkeri on Isla Nublar as of summer 2004

The central valley was gradually developed into three overlapping attractions: Triceratops Territory in the west, the Gyrosphere attraction in the south, and Gallimimus Valley in the east. Parasaurs were noted to chiefly inhabit the latter, but their actual range permitted them to venture across Sectors 4 and 6 of the park. As of December 18, 2015, parasaurs could be seen as far east as the Jungle River and as far west as Gyrosphere Valley. Two adults of the orange-skinned variety were seen on the river’s eastern bank, while an additional nineteen were seen in the valley. In the cave section of the Cretaceous Cruise’s River Adventure, four adults with bioluminescent traits could be seen. At least one juvenile was present in the Gentle Giants Petting Zoo at that time.

Additionally, some parasaurs were found in the island’s north. At least seven adults of varying brown and gray color schemes lived in the herds of Sector 5 near Camp Cretaceous’s Observation Tower, spending their days in the grazing areas and their nights in the nighttime paddocks. These are the first confirmed parasaur herds to integrate multiple color schemes.

Range of P. walkeri (red) on Isla Nublar as of December 18, 2015

After the 2015 Jurassic World incident, the parasaurs were free to roam across the entire island rather than just the central valley. Many crossed into the mountainous north, particularly after geomagnetic activity centered around Mount Sibo began in 2017. The parasaurs primarily lived in the forested foothills of the volcanic mountain. New predators abounded on the island, devastating the parasaur population. As volcanic activity increased, the animals were threatened by inhalation of hydrogen fluoride, as well as pulmonary exposure to volcanic ash. According to the Dinosaur Protection Group, Parasaurolophus was one of the island’s most threatened species as of 2018. The bioluminescent variety would likely have become extinct; even if they avoided becoming poisoned by the toxic algal bloom in the river, they would have been easy targets for predators since they lacked the ability to hide.

Known (red) and hypothetical (purple) range of P. walkeri on Isla Nublar between December 18, 2015 and June 23, 2018

As of June 23, 2018, just a single parasaur was seen on the island. It was driven westward by the eruption of Mount Sibo, taking the plunge over the northwestern cliffs into the Pacific Ocean; it was seen attempting to climb onto a rock afterward, but was unable to climb on. While other parasaurs lived in the area, this was the last one seen in the wild. It likely drowned; even if it reached shore safely, it would probably have perished due to the eruption or the loss of its food sources. A parasaur was seen being loaded onto the S.S. Arcadia by mercenaries led by Ken Wheatley as the eruption proceeded, and was removed from the island along with at least three others of its kind. With only four known specimens still alive as of the eruption, this hadrosaur was well on its way to extinction already. All of the survivors belong to the orange-skinned variety.

Isla Sorna

InGen originally bred Parasaurolophus on Isla Sorna, most likely in the Embryonics building. The date at which they were first cloned is unknown, but the earliest possible date is 1986. As they neared maturity, InGen would determine whether they were suitable for Jurassic Park; the animals that were deemed worthy were shipped to Isla Nublar. At least fifteen female parasaurs were chosen for this purpose. When Isla Sorna was last monitored in 1993, there were thirteen animals left; they were able to roam the island freely after Hurricane Clarissa forced InGen to evacuate. The population may have declined due to the release of predators; the carcass of an 18-foot subadult may have been found in the West Pacific by a Japanese fishing vessel in 1997, based on deleted concepts from the script of The Lost World: Jurassic Park. However, the animals reproduced quickly, replacing members of their species that had died off and beginning to grow the population.

Parasaurs were known from a few locations on Isla Sorna in the years between 1993 and 2004. The island’s northeastern game trail was known to host a herd of bachelor males, with between ten and seventeen adults being sighted on November 2, 1997. One of the males was captured by the InGen Harvester expedition, but was released by animal rights activists that night. He was released into the forest where the hunters had set up camp; it is not known if the parasaur migrated back to the game trail or found a new territory. The carcass of a subadult was seen in the tyrannosaur nest, located some distance to the south and farther inland, suggesting that parasaurs may live near here. Another carcass, also a subadult, was seen in the central part of the island near the Field of Nightmares and the Workers’ Village, confirming a parasaur presence near that region as well. All of the live male parasaurs seen in 1997 were of the brown-skinned variety, though the decay on the carcasses made proper identification of the skin color impossible.

The parasaur population had exploded by 2001, with at least two distinct herds being sighted between July 18 and 19. The southwestern grasslands housed a herd of fifty-five animals, including fifty-one adults and four subadults. A carcass of a subadult was seen near the airstrip, likely having belonged to this population. Somewhat to the east, in a grassland near the Embryonics, Administration, and Laboratories Compound, a herd of at least thirty-one animals was seen, one of which was a subadult. A further three adults were seen on the eastern bank of the central channel. All the individuals in the western part of the island were gray-green or beige in color, unlike the earthy brown males seen in the northeast. The junior novel Prey describes a green-colored individual living near Mount Hood as of December 31, 2001.

As of 2001, there were around eighty-nine Parasaurolophus living in western Isla Sorna, assuming that the two herds seen in the grasslands were unrelated. If the western population does not overlap with the eastern one, there may have been as many as 109 parasaurs on Isla Sorna between 1997 and 2001, an astounding increase from the thirteen animals that lived there in 1993. Along with natural reproduction, the parasaur population may have been bolstered by illegal cloning activity perpetrated by InGen between late 1998 and mid-1999; InGen’s new owner, Simon Masrani, visited Isla Sorna in 1999 and encountered a baby Parasaurolophus, indicating a recent breeding season.

Known (red) and possible (purple) ranges of P. walkeri on Isla Sorna between 1997 and 2001

Beginning in 2004, scientists noted an alarming decrease in the population of animals on Isla Sorna. The island’s small size and enormous population caused a trophic cascade as competition for food became intense and new predators unbalanced the ecosystem. Many of the parasaurs may have starved to death or died while competing with other, more formidable animals. In 2004, InGen began the process of relocating Isla Sorna’s animals to Isla Nublar, both for their own well-being and to stock Jurassic World. According to officials, there are no dinosaurs currently living on Isla Sorna, though the island is still restricted and poaching vessels were apprehended in its waters as recently as the mid-2010s.

Other

While Parasaurolophus was one of the intended species to be housed in Jurassic Park: San Diego in 1997, none were successfully removed from Isla Sorna at that time. Some may have been targeted by poachers between 1997 and 2018, but this is unknown. They were not confirmed on the mainland until June 24, 2018, when at least four adults from Isla Nublar were relocated to the Lockwood estate to be sold at auction. None are known to have been sold, with all known specimens being released on the night of June 24 due to a hydrogen cyanide gas leak in the manor threatening the animals’ lives.

Film footage of flyfishers encountering a Parasaurolophus in 2019

After fleeing into the surrounding forest, the parasaurs have gone on to roam the Pacific Northwest. At least one animal may have been relocated intentionally; a film surfaced in 2019 showing a parasaur drinking from a river in the Arkansas Ozarks, probably near Beaver Lake. The great distance involved heavily implies human intervention. This parasaur appears greenish-brown in color, differing from those released from the manor; since no breeding has yet been confirmed, it is suspected that this animal’s color has simply faded in the intervening time due to hormonal or other health changes.

Behavior and Ecology
Daily Activity

Paleontological research and behavioral evidence in the modern day both demonstrate that this is a diurnal animal, adapted to daytime activity and sleeping at night. Its large eyes would allow it to see relatively well in shady conditions, but it is not believed to be active at night unless disturbed. All observations of parasaurs in the wild have been during daytime and evening, except for incidents where the animal was unnaturally disturbed at night. Around midday, Parasaurolophus forages and bathes, and it rests during the heat of the day. It is more likely to spend its evening socializing, reaffirming the social bonds that protect them from danger.

Diet and Feeding Behavior

Parasaurs are efficient herbivores, capable of chewing their food with dental batteries consisting of hundreds of small, tightly-packed teeth. They chiefly feed low to the ground, though they are able to rear up onto their hind legs and reach food higher up in trees as well. Because they can chew, parasaurs can eat virtually any kind of plant they find; they are typically seen eating ferns, shrubs, and other ground plants. Since they inhabit coniferous forests, they may feed on the cones of trees such as the redwood as well as other fruits, but they have also been introduced to deciduous forests and lush tropical jungles with great success. The InGen IntraNet website lists its common food items as ferns, tree leaves, and aquatic mosses. Low-growing wetland plants were also documented in the diet of Dr. Laura Sorkin’s specimens.

If a parasaur discovers food, it will use a hooting cry to summon its herd members. This is sometimes interpreted as an act of altruism, but it also ensures that the social bonds between members of the herd are reinforced, and ensures that feeding occurs as a group.

These animals are often seen grazing or browsing in large herds, typically in open fields or at the edges of forests. This makes it easier to spot approaching danger, so they are able to drop their meal and easily flee if trouble comes along. Parasaurs value their lives more than food, and so will abandon anything they are eating as to not be distracted or encumbered while fleeing a predator. If deprived of food for too long, their behavior patterns become more unruly, in comparison to their usual docile manner.

In the game Jurassic World: Evolution, the favored food of Parasaurolophus is palm leaves, though it also enjoys conifers, ginkgoes, and rotten wood. It cannot digest grasses, horsetails, and cycads; these are harmful to its health. Specimens in Jurassic World in 2015 were seen grazing on grass, suggesting that they will eat this plant even though it is unhealthy for them.

Social Behavior

Like most hadrosaurs, the Parasaurolophus is a highly social creature forming herds that can become quite large (sometimes in excess of fifty animals). While it is of only average intelligence for a dinosaur, its social behaviors are advanced; parasaurs are sociable and playful, generally friendly creatures that strongly prefer to live in the company of others. Their social politics are surprisingly complex, with cliques forming based on coloration, particularly of the crest. Parasaurs are more likely to bond with other individuals with similar crest coloration, and in males, the vividness of an animal’s color is tied to its dominance in the herd. This is probably why parasaurs of similar coloration are often seen together, as less colorful animals seek one another out rather than remain alongside more impressive specimens. Dominance in females is based on resonance of voice, rather than coloration, according to the InGen IntraNet website, with lower frequencies being considered more authoritative.

Note the parasaur assuming a tripod pose in the middle. This individual is acting as lookout for her herd and will alert them if she senses danger.

The social herding behavior of Parasaurolophus is not just for comfort, but for safety. A lone animal, if targeted by a predator, would be easily killed. If it lives in a herd, though, it does not have to outrun its predator; it simply has to outrun the slowest member of its herd. Each individual parasaur’s chance of being killed is lower when in larger numbers, as the predators kill the weakest or unluckiest animals. This does not mean that parasaurs do not care for their own, however. As they forage for food or drink, at least one animal keeps a lookout for predators or other dangers; sometimes, a disabled parasaur will become watchman for its herd. Disabled animals have a greater motivation to notice approaching predators, as they are less able to defend themselves, so they are particularly alert and quick to notice danger. The watchman will often assume a tripod position, rearing onto its hind legs to give itself a better view. If it senses danger, it will emit a low groaning cry that signals caution to the others. The whole herd will flee as a single unit the instant danger is spotted. Juveniles will be sheltered in the middle of the herd for their safety. Even when only in pairs, parasaurs will take turns watching for danger while the other drinks or feeds.

Some parasaur actions, such as food signaling and watchman behavior, are interpreted as altruism by some scientists and laypeople (including Dr. Sorkin, who compared them to meerkats). However, it is argued by others that true altruism does not occur in nature, and that there are other reasons for the parasaurs’ behavior to have evolved this way. Signaling that food has been found summons other parasaurs, potential competitors, but also ensures that feeding occurs as a group so that if predators attack, each individual parasaur’s odds of survival is increased. Acting as watchman increases a parasaur’s value to the herd, and therefore that animal’s status. It also makes the watchman the one most likely to spot danger, and therefore increases its own individual chances of survival compared to its less alert fellows. However, lookout parasaurs have been observed waiting for their fellows to move away after hearing a danger call, only moving on once they were sure that the rest of the herd was safely moving out of the dangerous area. This is the closest to true altruism that has been observed in Parasaurolophus yet.

Competition within the herd is usually non-combative, since the parasaur has little in the way of weaponry save for its bulk. When two parasaurs do engage in combat, the challenger will make a groaning sound to start the fight. The combatants will make lunging motions and bellow at one another; if neither one backs down, the defending animal may initiate physical combat by shoving the challenger. Eventually, one of the animals will concede.

In the game Jurassic World: Evolution, this dinosaur forms herds of four to fourteen animals, though far larger groups have been reported in the film canon proper.

Reproduction

As with all dinosaurs, Parasaurolophus lays eggs and possesses a cloaca which houses its reproductive organs. The cloaca is located posterior to the hips, on the underside of the tail. Courtship involves visual and auditory displays, since these are the dinosaur’s main senses. According to the InGen IntraNet website, courtship occurs along social lines, with equally dominant animals in the herd hierarchy mating with one another. Males with brighter crest and body coloration, and females with lower-frequency voices, are considered more dominant; herd members with equal status based on these criteria will pair up during mating. The parasaur mating call is a low-pitched, even-toned moan; upon hearing this call, a receptive parasaur will respond with the same sound and move toward the source. In a research experiment by Dr. Laura Sorkin and David Banks, female parasaurs were found to respond to recorded mating calls which had actually been produced by females in the same social group. This may simply mean that both males and females produce identical mating calls, but homosexual behavior is common in modern-day birds and likely occurs in non-avian dinosaurs with similar frequency.

Mature form of P. walkeri bred for Jurassic World in later stages. The cloaca is visible as a small bulge behind the hips.

Incubation of eggs in larger dinosaurs such as Parasaurolophus usually takes around six months to a year, and amorous behavior has been observed in mid-June. This suggests that courtship and mating take place during the summer, which in Costa Rica would be the rainy season. Eggs probably hatch later in the year; depending on how long the incubation period lasts, they may hatch during the dry season, or at the beginning of the next rainy season.

Most hadrosaurs practice parental care, with the mother of the hatchlings providing food and protection. Juveniles are sometimes observed alongside the adults in herds; none were observed within a group of males in November 1997, but were observed in other herds in July 2001. Only a few subadults and younger animals could be seen, suggesting a higher mortality rate despite the animals’ large population increase. To protect the younger parasaurs, adults will surround them to keep the young ones on the inside of the herd, and keep a watchful eye out for predators at all times.

Fossil evidence suggests that parasaurs mature more rapidly than other hadrosaurids, reaching their adult proportions in a year or so. This may explain why juveniles are so rarely observed; those that survive become adults by the time the next breeding season occurs. Crests of juveniles quickly grow to the shapes of the adult crests, suggesting that juveniles are capable of vocalizing like the adults from a young age.

Communication

Among the most vocal of dinosaurs, Parasaurolophus has a sophisticated system of communicating with members of its own kind that surpasses that of other herbivores. The InGen IntraNet website describes it as a primitive language, on par with modern-day monkeys, a description that has also been applied to the much more intelligent Velociraptor.

Parasaurs are among the most socially advanced of dinosaurs, despite having only average intelligence.

Much of our understanding of parasaur communication comes from the research of Dr. Laura Sorkin and her assistant David Banks in early 1993. Three specific calls were studied and interpreted with full confidence: the food call, mating call, and warning call. The food call is an upswept hooting sound, used by a parasaur that has found a viable source of food to summon its herd. This ensures that feeding occurs as a group, keeping all the animals safe and together. The mating call, as described above, is a low-pitched moan, used in a call-and-response manner to initiate courtship. The warning call is a loud groan, emitted when a parasaur senses danger. When a warning call is emitted, it is not an instant cause for panic, and instead instructs the other parasaurs to begin moving away from the area before danger arrives. Louder and higher-pitched alarm calls are instead used when the animal is frightened; if these calls are made, the herd is likely to stampede.

If confronted with danger, such as during stampedes, parasaurs have been heard making loud trumpeting and bellowing sounds. The bellowing sounds in particular sound very similar to the noises made by agitated Stegosaurus and Triceratops, and are used under similar circumstances. Parasaurolophus uses these bellows when stampeding but also during dominance displays, suggesting that it is an intimidation cry rather than a sign of panic. When it uses these sounds while being hunted or otherwise threatened, they serve to warn other parasaurs as well as to try and intimidate predators. The volume of the call advertises the parasaur’s health and vitality, giving both predators and competitors reason to choose another target.

Other vocalizations are not as well-studied, but have been observed nonetheless. The animals will make various hooting and snorting noises to communicate information to one another; small hoots are sometimes heard when a parasaur notices a new object or animal in its environment, in contrast to the huffing sound it makes when startled.

Parasaurs also engage in other forms of communication including visual displays. The crest is its most prominent feature, and is used to signal other members of its species; it is distinctly different in shape from the crests of other hadrosaurs such as Corythosaurus, enabling it to recognize its own kind. Males in particular use their coloration to communicate, establishing dominance hierarchies among one another and advertising their virility to females. Both body language and vocal sounds appear to be universal across parasaur populations, rather than varying from one social group to another.

Ecological Interactions

Not only is Parasaurolophus social, it commonly interacts with members of other species. It prefers the company of sauropods, such as Brachiosaurus, Mamenchisaurus, and Apatosaurus; parasaurs are seldom seen far from these huge herbivores’ feeding grounds. With such large neighbors around, they are more likely to be protected from danger; only the largest of predators would dare confront a sauropod. The wary parasaurs have excellent senses, and therefore can assist the sauropods in detecting danger, making it a mutualistic form of symbiosis.

Herd of Parasaurolophus and Corythosaurus, Isla Sorna (7/18/2001)

Parasaurs are also often sighted alongside other hadrosaurs, particularly Corythosaurus. They have been seen living peacefully in integrated herds with this species, relying on safety in even greater numbers than they would have alone. Corythosaurus uses different vocalizations, but the two genera appear able to recognize one another’s more important social cues such as warning signs. In fact, Parasaurolophus appears quite good at recognizing the warning signs given by numerous other animal species, and reacts accordingly. The game Jurassic Park: Operation Genesis states that its favored companion is Edmontosaurus, another hadrosaur that it is known to have coexisted with on both Isla Nublar and Isla Sorna. It has been documented forming associations with Gallimimus and Pachycephalosaurus, and appears to be able to live alongside armored herbivores such as Ankylosaurus, Stegosaurus, Peloroplites, and Sinoceratops without issue. The territorial Triceratops is a less friendly neighbor, but Jurassic World’s animal behaviorists were able to coax these animals into sharing their home with the more mild-mannered parasaurs. It also inhabits areas that are home to the smaller herbivores Microceratus and Stygimoloch, but its relationship to them is less understood. Modern birds are frequently seen living in or near parasaur herds. The birds use these huge animals for protection, and probably feed on trampled plants or insects that are stirred up by the hadrosaurs’ movements.

Like all herbivores, the parasaur shapes its environment by eating it. Their grinding teeth and jaws adapted for chewing permit them to feed on most types of plants; some individuals in Jurassic World have even been observed grazing on grass, which dinosaurs are not actually evolved to eat. They tend to live in or near coniferous forests when left to their own devices, with pines and redwoods being common in their habitats; they may feed on the cones of these trees, as well as fruits and leaves of other plant species. Ferns constitute a large amount of their diet, as do other low-growing plants. Forests also help them avoid danger, since they can more easily hide, and larger carnivores have difficulty navigating through denser forests and jungles where parasaurs are quite comfortable.

Illustration of predatory activity of Tyrannosaurus rex on Parasaurolophus walkeri. Image courtesy of the Dinosaur Protection Group.

It has a few defenses against predators, such as its bulk, speed, and intimidating bellows. Not all enemies can be crushed, outmaneuvered, or frightened; for these persistent predators, parasaurs rely on numbers for protection. When they herd with similarly-vulnerable neighbors, they have been witnessed shoving members of other species out of the way during stampedes; they probably only do this when it would increase their own chances of survival, as it has not been observed occurring with armored herbivores (since this might injure the parasaur). Confirmed predators include Tyrannosaurus and Velociraptor, though carcasses may be scavenged by small carnivores such as Compsognathus. Waterways on Isla Sorna put them in proximity to the fish-eating Spinosaurus, Baryonyx, and Ceratosaurus, though predation of these animals on Parasaurolophus has not been directly documented. On Isla Nublar, they would have also encountered Suchomimus and Metriacanthosaurus at the Jungle River, as well as TeratophoneusAllosaurus, and Carnotaurus near Mount Sibo. The territorial pterosaur Pteranodon was known to live near Mount Sibo too, and is known to prey on juvenile dinosaurs.

Juvenile Parasaurolophus, along with juveniles of other herbivores Ankylosaurus, Styracosaurus, Protoceratops, and Pachycephalosaurus. Concept art by Shaun Keenan.

Along with its large predators, Parasaurolophus is impacted by disease and parasites. In the Cretaceous period, it was bitten by female mosquitoes which used its blood to nourish their eggs; it is unconfirmed whether modern mosquitoes also bite them. They are susceptible to bacterial infections leading to osteomyelitis, which Jurassic World’s paleoveterinarians observed affecting the intracranial bone. The most common cause of osteomyelitis is infection from the bacterium Staphylococcus aureus, though other bacteria and even some fungi can cause it. If a parasaur suffered osteomyelitis in any of its cranial bones, the function of its crest could be impacted, leading to the animal becoming socially isolated; in the wild, this would be a death sentence, since it relies on numbers for long-term protection. In Jurassic World: Evolution, parasaurs are particularly susceptible to avian influenza, which is typically caused by the influenza A virus.

Relationship to Humans

Parasaurolophus is one of the most consistently featured dinosaurs in de-extinction theme parks, with most people at least recognizing its distinctive appearance even if they might not know its scientific name. This dinosaur was first planned to be featured in Jurassic Park in the 1990s, being present in two different paddocks visible from the main road as well as an access road used to transport VIP guests and staff from the helipad. It was one of several dinosaurs that decorated the mural of Les Gigantes within the Visitors’ Centre, featuring both P. walkeri and the smaller Parasaurolophus cyrtocristatus, which was once incorrectly thought to be the female version of the larger species.

In addition, this dinosaur was studied extensively by paleogeneticist Dr. Laura Sorkin and her assistant David Banks, providing us with much of the information about parasaur behavior we have today. During the 1993 incident, Dr. Sorkin released her four parasaurs believing that they would be able to feed themselves in the wild until she returned; she was not aware yet that the park was slated for deconstruction. She also used the parasaurs as a justification to put her adenovirus-based cure for the lysine contingency into the Park’s water supply, which treated all of the dinosaurs on the island.

This animal was also intended to appear in Jurassic Park: San Diego, which aimed to open its doors by the end of 1997. InGen CEO Peter Ludlow, who replaced Dr. John P. Hammond earlier that year, had listed this species as one for the Harvester expedition to capture; on November 2 they secured a single male parasaur for the Park. It was released by animal rights activist Nick Van Owen during the night; while the parasaur fled through the camp, it did not attack the hunters, instead fleeing while giving cries to intimidate them.

Parasaurolophus being loaded onto the S.S. Arcadia, 6/23/2018. This was the last member of its species to be removed from Isla Nublar.

It was finally put on exhibition in 2005 with the opening of Jurassic World. One of just eight species present when the park first opened, it consistently featured in three attractions of the island’s central valley: the Gyrosphere, Gallimimus Valley, and Cretaceous Cruise. In particular, a variety of parasaur was genetically engineered for the River Adventure section of the Cretaceous Cruise, modified with algal genes to exhibit bioluminescence, a trait they share with Stegosaurus. Juveniles were exhibited in the Gentle Giants Petting Zoo where guests could interact with them more closely. While parasaurs are not the most thrilling or famous of dinosaurs, their unique appearance and friendly, social nature endeared them to many guests. Many people find their communicative vocalizations to be hauntingly beautiful; since parasaurs frequently socialize in the evening, they would have enhanced Isla Nublar’s beauty as sunset approached.

Throughout 2017 and 2018, images of Parasaurolophus as a part of Isla Nublar’s ecology were often used by the Dinosaur Protection Group to garner support for the dinosaurs’ survival. The animal was portrayed as a vital part of the food web, sustaining the island’s larger carnivores. As the eruption of Mount Sibo became inevitable, the DPG reported that Parasaurolophus was in a particularly precarious position due to its proximity to the volcano. When the capture operation actually took place in June of 2018, only one wild parasaur was seen; the rest had been captured by the mercenary team led by Ken Wheatley. No parasaurs are known to have been sold at the black-market auction the following day, but multiple parasaurs were released into the wild.

Parasaurolophus among other animals during the 2018 incident, Lockwood Manor, Orick, CA (7/24/2018)

Parasaurolophus is not generally a dangerous or threatening dinosaur, as it is more likely to flee from danger and is non-aggressive. The main threat is being in the way of a frightened parasaur, as it is not likely to notice a human in its path while charging away from danger. This animal can weigh between two and four tons, making it easily capable of crushing a human, as has nearly occurred on a few occasions (notably during the 2001 incident on Isla Sorna). Only one occasion of parasaur attack has been noted, during the 2015 incident when Camp Cretaceous members in kayaks encountered four of these animals which unexpectedly became aggressive after approaching the humans. Docile as they may be, they should be treated like any other wild animal and given a respectable distance.

Behind the Scenes

Production-wise, we know from The Making of The Lost World (p.25) that gender differences were intentional in the design phase of pre-production to indicate differences between male and female versions of the animal.

“‘We had to design new paint schemes not only for the new dinosaurs, but for some of the already-designed dinosaurs from the last movie,’ Winston explained, ‘because now there were male dinosaurs, as well as females; and typically in nature the males of any species are far more brightly colored. We also wanted to make sure that the audience would be able to tell the males and females apart. It was a great of fun to run the gamut of color and come up with interesting designs. The colors on the females for the first film had been fairly subdued; but with male animals, there were may more possible colorations.’”

If the herds are indeed persistently gender divided, some have postulated that the Parasaurolophus females are territorial, and the source from this comes from an informational video at Isla Adventura. There is a concept art piece featuring a design of the female Parasaurolophus that doesn’t quite bear a similarity to what we see in the films as well. The many variances seen in Parasaurolophus could even be another example of versioning by InGen and we are in fact seeing both males and females together. We just can’t say for certain based on the information we have available to us.

Female (Conceptual Design by ‘yankeetrex’)
Based upon the female design for the Parasaurolophus
in the first film and Behind the Gates’ research
Male

Notable Individuals

Elvis – male parasaur targeted by the InGen Harvester expedition

Sorkin’s Parasaurs – group of 4 females in a 1993 behavioral study

Disambiguation Links

Parasaurolophus walkeri (S/F-Ride)

Parasaurolophus walkeri (C/N)

Parasaurolophus walkeri (JN)

Parasaurolophus walkeri (T/C)

Parasaurolophus walkeri (IDW-DG)

Parasaurolophus sp. (CB-Topps)