Brachiosaurus “brancai” (*) (S/F) / (S/F-T/G) (S/F-S)

Disambiguation Links – Brachiosaurus brancai (T/C) / Brachiosaurus brancai (*) (JN) / Brachiosaurus brancai (CB-Topps)

Brachiosaurus is a genus of extremely large sauropod dinosaur in the family Brachiosauridae known from the late Jurassic period, 154 to 153 million years ago. The closely related genus Giraffatitan, which most popular depictions of Brachiosaurus are based on, lived during a slightly broader span of time ranging from 150 to 145 million years ago. The first of these two to be discovered was Brachiosaurus; its name means “arm reptile,” in reference to its characteristically long forelimbs. It was first discovered near Fruita, Colorado in 1900, a location that is now part of the Morrison Formation. The specimen consisted of a partial skeleton, lacking a head, but was immediately recognizable for its distinctive anatomical features. In 1901, it was described in a report by paleontologist Elmer S. Riggs, who had excavated the skeleton during the previous year. At the time, it appeared to be the largest-known dinosaur; it was named Brachiosaurus altithorax, meaning “high-chested arm reptile,” in 1903. Remains of this dinosaur are rare, but have been found in Colorado, Oklahoma, Utah, and Wyoming.

Concept art of a mature female Brachiosaurus

Another species was discovered in 1906 by mining engineer Bernhard Wilhelm Sattler near the Tendaguru, a hill near Lindi in German West Africa (what is today Tanzania). The next year, the discovery had brought in paleontologist Professor Eberhard Fraas to investigate; research by German paleontologists at the Tendaguru would continue through 1912. The brachiosaur fossils themselves were excavated between 1909 and 1912, with the species being named Brachiosaurus brancai in 1914 by Werner Janensch. The specific epithet honors Carl Wilhelm Franz von Branca, the State Geologist for the Prussian Geological State Service, who considered the Tendaguru expeditions to be a matter of German national pride. A smaller, more poorly known species was later described as Brachiosaurus fraasi in honor of Eberhard Fraas.

The skull of Brachiosaurus was unknown until 1975, though it had actually been discovered far earlier. A skull discovered by Othniel Charles Marsh in 1883 was theorized by Jack McIntosh and David Berman in 1975 to have been classified incorrectly. McIntosh suggested that it might actually belong to Brachiosaurus, and this possibility was studied by Virginia Tidwell and Kenneth Carpenter over the next several years. In 1998, the skull was conclusively found to belong to Brachiosaurus, based on similarities to other brachiosaur skulls.

Yellow-striped color morph of Brachiosaurus

The validity of both Tanzanian species of Brachiosaurus was brought into question in 1991 by paleontologist George Olshevsky, who placed them into a new genus called Giraffatitan (intended to mean “titanic giraffe,” in reference to its giraffe-like posture). This was disregarded by many paleontologists until 2009, when paleontologist Michael P. Taylor supported the classification. It has been largely supported by the paleontological community since. The two genera are very similar, but can be distinguished by the larger size of vertebrae and longer, taller tail in Brachiosaurus.

Brachiosaurus fraasi is now considered to be the same species as Giraffatitan brancai, and neither genus is currently known to have any other species than those discussed above.

International Genetic Technologies, Inc. succeeded in cloning Brachiosaurus in approximately 1986 utilizing mosquitoes and other parasites found in Jurassic amber samples. The species cloned is said to be B. altithorax on the InGen IntraNet website, and is referred to as Brachiosaurus in material released after the African species was reclassified. This all suggests that InGen cloned the North American Brachiosaurus altithorax rather than the African Giraffatitan (formerly “Brachiosaurus“) brancai. However, as the physical appearance of InGen brachiosaurs resembles Giraffatitan, Jurassic-Pedia staff have traditionally listed it as B.brancai“.


Brachiosaurus is famously among the largest of the dinosaurs, growing to lengths of 52 feet (15.85 meters); including its neck, its total head-to-tail body length can reach 70.5 feet (21.5 meters) to 90 feet (27.4 meters). When the neck is stretched directly upward, its height from head to feet can reach 30 feet (9.1 meters). An adult brachiosaur may weigh up to 60,000 pounds (27,215.5 kilograms), or thirty U.S. short tons. It is not the largest dinosaur known to science, though for around a century it was; today, larger dinosaur species have been discovered. It is the bulkiest dinosaur so far cloned by InGen, though it is not the longest, as this honor belongs to Mamenchisaurus sinocanadorum. The marine reptile Mosasaurus maximus may grow longer than both if the conditions are proper, though it is not a species of dinosaur. Like all dinosaurs, Brachiosaurus is endothermic and maintains a warm internal body temperature. Its blood pressure is very high, about twice that of a giraffe’s, in order to pump blood from its huge, powerful heart all the way up to its brain.

Giraffatitan fossils are generally somewhat larger than those of Brachiosaurus, though InGen’s specimens have a size range that spans those of both genera. It has been suggested that genetic hybridization between these two genera of brachiosaurs may have taken place, but there is currently no confirmation or denial of the hypothesis.

The anatomy of brachiosaurs such as Brachiosaurus differs strikingly from that of other sauropods. Contrasting with the classical “brontosaurian” profile of genera such as Apatosaurus, this dinosaur’s front limbs are noticeably longer than its hind limbs. This places most of the dinosaur’s weight in the front of its body and gives its back a distinctive slope; its shoulders are placed higher than its hips, meaning that its already long neck starts at a greater height than other sauropods. It is able to rear up onto its hind legs (it is questionable whether the fossil animals could have done so), but it has little need to reach any higher than it already can, so it rarely does this.

Its neck is generally held mostly upright, though fossil remains indicate that a forty-five or sixty-degree angle would be more natural. The neck terminates in a proportionately small head, which has a shorter and wider snout than many other sauropods and tall nasal chambers forming a kind of crest. InGen’s Brachiosaurus has nostrils located on its broad forehead, which may or may not be a phenotypic error. Other skull features are fairly normal of sauropods; the teeth are chisel-like and the eyes possess birdlike, round pupils and orange sclerae. Brachiosaurs have excellent color vision and can distinguish different patterns, even responding emotionally to certain patterns and colors over others. Its jaw is more mammalian than dinosaurian, however, permitting it to chew its food unlike its fossil counterparts. The tongue is thick, somewhat pointed, and usually a pinkish color.

Hind-foot print of a Brachiosaurus. Image from the Dinosaur Protection Group

Like most sauropods, the front and hind feet have differing numbers of toes. On the front feet, Brachiosaurus has only one clawed toe; the hind feet have three visibly clawed toes and one toe that lacks a claw. The remaining toes on all of its feet are harder to distinguish and may not appear visible. All four of its limbs are extremely powerful and pillar-like, necessary adaptations to support this huge animal’s weight. The body is thick and barrel-shaped, though it narrows toward the hips; its tail is comparatively short, unlike the long, sinuous tails of other sauropods like Mamenchisaurus and Apatosaurus.

Two color morphs are known in Brachiosaurus. The best-known morph, though it was historically less common, exhibits a tan or gray-brown coloration over most of its body; the underside is often countershaded with lighter brown or tan. There may be teal or turquoise patterning on the nasal dome. The second morph, which was once much more common, is a tan or beige color with yellow mottling over the entire body, including darker striping on the necks of some individuals; there is also countershading in this morph. The nasal dome and sides of the face are bright red. It is not currently known if any of this color morph are still living; it may have become extinct.


Hatchling Brachiosaurus have not been observed directly, but have appeared in supplementary sources. Concept art for the canceled 1990s Jurassic Park animated television series, the mobile game Jurassic Park: Builder, 1993 collector cards, and others have generally depicted hatchling Brachiosaurus as having proportions and coloration similar to the adults. However, the neck is generally shorter and the back proportionally longer in the juvenile.

A herd of Brachiosaurus, Isla Sorna (7/18/2001). Note the juveniles located to the bottom and left of the image, as well as the variable colors of the adults. The alpha male can be seen grazing.

Adolescence is reached at around six years of age in this dinosaur. The adolescents have proportions more like the adults at this age, though they tend to be skinnier and more lightweight. Skeletal maturity is reached in around ten years. Even after the full size is reached, coloration may change somewhat as the animal ages; increased age has been known to bring a general darkening of color over the dorsal side as well as new color patterning on the head.

Adulthood is reached in roughly ten years. Its lifespan is unknown, but some sources suggest that it may live for one or two centuries.

Sexual Dimorphism
The vibrant red head and stripes of the lead Brachiosaurus here suggest that it is a male.

At one point, the two color morphs were suggested to be sexually dimorphic (with the gray or brown morph as the female and the yellow morph as the male), but there is no evidence to confirm this. Females of the gray or brown morph have been observed, but none have been confirmed to be male.

In the yellow morph, at least one male was positively identified by Dr. Alan Grant. Some members of this morph can be seen to have more vibrant colors, including brighter red nasal domes and bold, dark stripes on the back of the neck. It has been suggested that these more vibrantly-colored animals are the males of the yellow morph.

Preferred Habitat
Brachiosaurus in a densely forested area, Isla Nublar (6/11/1993)

Because of its huge size, Brachiosaurus requires room to roam as well as access to very large quantities of food. It is generally observed in large ranges containing open grassland, forests, and larger bodies of water; its habitat usually consists of flatter areas. Water sources are not only necessary for hydration, but for health, as this dinosaur bathes regularly for hygenic purposes. It cannot, however, survive in deep water; if submerged too deeply, the water pressure will be too great for it to inhale, and it will suffocate even if its neck and head are above the surface.

Fossil evidence suggests that they could have inhabited seasonal floodplain environments with some coniferous forests nearby. As such a large animal, it would create scrubland and prairie as it traveled through its environment by knocking down trees and trampling smaller plants.

In the game Jurassic World: Evolution, a habitat for Brachiosaurus needs to include at least 21,000 square meters of forest and 21,000 square meters of grassland.

Isla Nublar

InGen introduced this species to Isla Nublar beginning in 1988 at the earliest. Brachiosaurus were kept in two different herbivore paddocks which they shared with Parasaurolophus. The primary such paddock, located somewhat farther to the north, was heavily-forested to the east and open and grassy to the west. It bordered the secondary Dilophosaurus paddock to the north, the Velociraptor and Tyrannosaurus paddocks to the east, and the Gallimimus paddock to the southeast. Twenty-four-foot electric fencing kept these animals separate. The remainder of its borders were separated from the main tour road by a moat. The secondary herbivore paddock, located farther south and centered around the Watering Hole, also consisted of both forested and open regions. It bordered the Park’s perimeter fence to the west, the Jungle River to the south, and a service road to the east and north; on the other side of this service road, separated by a five-foot electric fence, were the future Proceratosaurus paddock in the north and an undeveloped area of land to the east.

As of June 11, 1993, there were three adult females of the gray/brown morph in the secondary paddock; five adult females of the gray/brown morph were later seen in the primary paddock that evening. However, official InGen reports state that, at the last point that Isla Nublar was monitored in 1993, there were six brachiosaurs on the island. This suggests that either two of the brachiosaurs died during or shortly after the incident itself, or that the animals from the secondary paddock escaped and entered the primary paddock during the tropical storm that struck on June 11 while the electric fencing was turned off.

Paddock range (red) of B.brancai” on Isla Nublar prior to June 11, 1993

Following the 1993 incident, the Brachiosaurus remained more or less within the area defined by their original paddock range. The 1994 cleanup operation on Isla Nublar reported as of October 5 that one of the brachiosaurs had died due to malnutrition in the intervening time.

Known (red) and hypothetical (purple) range of B.brancai” on Isla Nublar between June 11, 1993 and 2002

Beginning in 2002, InGen returned to Isla Nublar as a member of Masrani Global Corporation with the intention to rescue the abandoned Jurassic Park project. Between 2002 and early 2004, the surviving Brachiosaurus were temporarily relocated to Isla Sorna. The first to be reintroduced to the island were two mature females which park staff dubbed “Olive” and “Agnes;” these animals were among the oldest of their species, and were among the five survivors from the original Park. They were introduced to the Gyrosphere Valley area sometime prior to January 15, making them the first herbivores in that region of the island. By the summer of 2004, a six-year-old adolescent female named “Pearl” and a slightly older adolescent named “Dot” had also been introduced to the valley. InGen Security’s Asset Containment Unit had considered relocating Pearl to a more isolated habitat due to behavioral concerns, but as of September 2004 these plans had been cancelled and Pearl remained with the other brachiosaurs in the valley. During that summer, eggs from this species were also incubating in the Hammond Creation Laboratory, but none had yet hatched by autumn.

Between late 2004 and Jurassic World’s opening date on May 30, 2005, the remaining Brachiosaurus from Isla Sorna were all introduced to Isla Nublar. Some likely resided in the valley, while others may have been maintained in habitats located in Sector 5 away from visitors. Their population statistics are mostly unknown between 2005 and 2018.

Brachiosaurus were actively bred on the island during this period of time. At least one gray morph female was confirmed to have hatched between May 16, 2006 and May 15, 2007; this individual was said to be an eleven-year-old adult as of May 15, 2018 and was still living at that time. The yellow morph appears to have disappeared by 2018, suggesting that the gray/brown morph is dominant when the two interbreed.

Eventually, however, the Brachiosaurus were relocated out of the Valley and introduced to habitats within Sector 5. This was likely sometime shortly before 2014; Brachiosaurus was not advertised on official park merchandise or the Jurassic World website, but its silhouette could still be seen on the Gyrosphere Valley map schematic. InGen was planning a new attraction called Treetop Gazers which would have housed the brachiosaurs; this attraction would have opened in 2018, but its planned location is currently undisclosed. The Sector 5 habitat for the brachiosaurs may have been anywhere within ten miles of Owen Grady’s bungalow, as the brachiosaurs’ cries are audible from that location. However, Apatosaurus make similar sounds, making it unclear which species was heard at that point.

Treeop Gazers never opened, leaving the brachiosaurs out of the public eye until after Jurassic World closed on December 18, 2015. With the park’s restraining technologies deactivated, the animals could roam freely about the island. They appear to have ranged across Isla Nublar as of 2018; they have been sighted primarily in the north, but also the central and eastern parts of the island. An artistic depiction by the Dinosaur Protection Group depicts three brown-morph adults living in the remains of the old tyrannosaur paddock, though this may not be based on actual observations. Footage of two adult and one subadult gray/brown Brachiosaurus, possibly a family group, was captured sometime prior to June 22, 2018; this footage was featured prominently in a BBC news segment regarding Isla Nublar. Other records indicate that these animals inhabited the Gyrosphere Valley area as of 2018, along with a likely presence in the north near Mount Sibo. A single adult gray-morph brachiosaur was sighted on Main Street on June 23; this individual along with at least two others of the same color morph were driven eastward by the volcanic eruption occurring on that day, all of which perished. At least one gray-morph brachiosaur was removed from the island via the S.S. Arcadia; its 26,520kg (58,466.59lb) weight indicates that it was an adult. Additionally, the skeleton of a subadult-sized animal was obserbed near Radio Bunker 02-17 on June 23.

Together, this means that there were a minimum of five brachiosaurs on Isla Nublar between the 2015 incident and the eruption in 2018, and that there were at least four actually living on the island on June 23. This estimate assumes that the three which were remotely recorded included the brachiosaur captured by Wheatley’s team and/or the skeletal remains found near the radio bunker, and/or that the subadult had matured by June 23. It is entirely possible for the three animals in the recording, the three seen during the eruption of Mount Sibo, the skeletal remains, and the animal captured by Wheatley’s team to have been different creatures, meaning that there would in that case be at least eight brachiosaurs on the island at the time.

According to film director J.A. Bayona, the Brachiosaurus which is last seen on the East Dock on June 23, 2018 is the same individual seen on Main Street earlier that day, as well as being the same individual that was first seen on June 11, 1993. It is possible that this animal was Agnes, as the lack of a distincive neck scar means it cannot be Olive, but it may also be another unnamed brachiosaur from the original Park that was brought to the island after September 2004.

Following the June 23 eruption of Mount Sibo, Brachiosaurus is extinct on Isla Nublar.

Isla Sorna

Brachiosaurus was likely among the first dinosaurs cloned by InGen. Two older females were said to be “in their twenties” as of August 2004, which is slightly incorrect; the first dinosaurs were cloned in 1986, so the oldest the brachiosaurs could have been at the time would be 18. Nonetheless, it appears that Brachiosaurus was cloned fairly early on. Between six and eight brown-colored females were eventually shipped to Isla Nublar between 1988 and 1993; most of the adults seen on Isla Sorna from then on appear to be of the yellow morph.

It is not known exactly how the population dynamics of this animal on Isla Sorna changed over time. According to the InGen IntraNet website (which was created to promote Jurassic Park: The Ride as well as tie in with the 1997 film The Lost World: Jurassic Park), InGen’s first brachiosaurs were introduced to a lagoon environment with the assumption that they were semi-aquatic. The website states that this resulted in the deaths of the animals, and subsequent clones were introduced to grassland areas instead. The website also indicates, in hidden emails, that InGen Security may have clandestinely poisoned some of the brachiosaurs in order to eliminate what they believed was a waste of resources. The canon status of these statements is currently unknown, but by the time InGen abandoned Isla Sorna in 1993, there were ten living brachiosaurs left on the island.

A herd of Brachiosaurus can be seen on the left. The adults are likely those hatched in the mid-1980s, while the smaller subadults are probably their offspring. The brachiosaur population on Isla Sorna more than doubled between 1993 and 2001, a period of eight years.

In Eric Kirby‘s book Survivor, an unnamed sauropod is seen on the island’s western coast on May 23, 2001; illustrations indicate that it may have been an adult or subadult Brachiosaurus. Evidence of sauropod feeding grounds existed farther inland, though no animals were there at the time. Roughly eight weeks later on July 18, his rescue team observed a large group of yellow-morph brachiosaurs on a grassy plain in the island’s western region; the herd consisted of at least twenty-five animals led by an alpha male. Five subadults and two juveniles could be seen in the herd. The following day, four yellow-morph adults were seen on the central channel’s eastern coast, inclduing one more vibrantly-colored animal which may have been a male.

While the brachiosaur population’s growth rate is surprising, it is not impossible given the time frame during which it occurred. If the adult brachiosaurs had reproduced in 1993, their offspring would be nearing adulthood by 2001; with a total adult population of between 18 and 23, eight to thirteen of the 1993 season’s hatchlings would have had to survive to adulthood. The five subadults and two juveniles seen in 2001 would have hatched in the intervening years.

The Brachiosaurus named Pearl was six years old as of August-September 2004, meaning that she hatched on Isla Sorna between the autumn of 1997 and the summer of 1998. She would have been three years old in 2001, so she is likely not one of the juveniles seen during the 2001 incident; however, the brachiosaur Dot was born a year or two earlier, and may have been one of the juveniles seen at that time.

Known (red) and estimated (purple) range of B.brancai” on Isla Sorna as of 2001. The actual range of this animal is likely to be considerably larger owing to its habitat and dietary needs.

Between 1998 and 1999, InGen illegally performed genetic research and development on the island in violation of the Gene Guard Act. This led to an increase in dinosaur population on Isla Sorna, which imperiled the already unstable ecosystem. Furthermore, InGen retaking Isla Nublar in 2002 under the guidance of Masrani Global Corporation ended up introducing between two and five adult female brachiosaurs to Isla Sorna. In early January of 2004, two of the oldest brachiosaurs originally from Isla Nublar (named Agnes and Olive) were shipped back to Isla Nublar again. The animal populations of the island were collapsing at that point due to resource scarcity and poaching, prompting the remaining dinosaurs to be rounded up and transported between 2004 and 2005. Sometime during the spring or early summer of 2004, Pearl and Dot were shipped to Isla Nublar, and after September of that year any surviving brachiosaurs would also have been shipped over. Official sources claim that there are no brachiosaurs left on Isla Sorna today.


It is not known if any Brachiosaurus fell victim to poachers in the Muertes Archipelago or on Isla Nublar between 1997 and 2018, though if any were, they likely would have had to be juveniles. It is not likely that any would have fared well in illegal captive conditions on the mainland, as only a highly advanced and well-funded facility could provide for their needs.

At least one adult Brachiosaurus was removed from Isla Nublar via the S.S. Arcadia on June 23, 2018 by mercenaries headed by Ken Wheatley. It was housed at Benjamin Lockwood‘s estate overnight on June 24 and was released into the wild to save it from hydrogen cyanide poisoning. Its current whereabouts are unknown, though it was last seen fleeing into the woods near Orick, California.

Behavior and Ecology
Daily Activity

Brachiosaurus is diurnal, and can be seen feeding and bathing during the morning and midday. In the evening, they typically will rest and socialize; their singing may go on into the night. Social behavior can be observed throughout other times of day. Survivor describes a brachiosaur resting around midday; it sleeps standing up, which allows it to make a swift escape from danger. Resting and bathing around noon may help the animals avoid the heat of the day.

In the mobile game Jurassic Park: Builder, it is active for two-hour periods at a time.

Diet and Feeding Behavior
Female Brachiosaurus feeding on the foliage of a Moreton Bay fig tree (Ficus macrophylla)

As with all sauropods, Brachiosaurus has an enormous diet; it spends as much as sixteen hours a day feeding. It may consume around 400 pounds of foliage in a day, eating up to 130 pounds at a time (paleontological estimates suggest eating 440 to 880 pounds of food in a day would not be unreasonable). An adult brachiosaur feeding on one hundred or fewer pounds of food a day is cause for concern. A healthy food-to-waste ratio should be one pound of waste produced for every 4.3 pounds of food consumed, meaning that it digests around 77% of the food it eats. Excess fluid retention may be a health concern diagnosed by a lesser quantity of waste produced per amount of food eaten. Brachiosaurus produce copious amounts of dung and flatulence as a result of their diet.

This herbivorous animal is a forager and feeds on a wide variety of plant life. It primarily eats the leaves of trees; it has been seen to eat from monkey puzzle trees, Moreton Bay figs, eucalyptus, and palm trees. These latter two types of trees are known for their low nutrient content; fairly few animals can gain any useful nutrition from eucalyptus or palms, but Brachiosaurus appears to favor these and eats them even when other options are available. This may be an adaptation to avoid competition, choosing to feed on plants that other herbivores would not bother with. Fossil evidence suggests that they lived in environments with coniferous trees, such as members of the genus Araucaria, and in the modern day they are confirmed to feed on the monkey puzzle tree, which belongs to that genus.

The upward slope of this animal’s body is an adaptation to avoid competing with other sauropods, such as Apatosaurus.

The entire body of a brachiosaurid is designed with feeding in mind. It is built uphill, with its neck extending from the trunk at a fairly high angle. This allows it to browse on the highest trees, where other animals are unable to reach. InGen’s Brachiosaurus are exceptionally adept competitors for these resources; they are able to rear onto their hind legs to reach the absolute highest leaves, and are able to chew their food due to abnormally mammal-like jaw structure. This means that they do not require gastroliths to help digest their food. The nostrils, located on the forehead in InGen’s specimens, are sometimes believed to be an evolutionary adaptation to help the animal breathe while eating and drinking. However, not all paleontologists agree that the nostrils were located here in fossil animals, suggesting that this is a mutation in InGen’s brachiosaurs rather than a natural feature.

InGen’s IntraNet website describes a more unusual feeding strategy in this animal. It will use the claws on its hind feet to uproot brush and other low-growing plants, using its front feet for support while it does so. After tearing up the undergrowth, it will eat as it pleases. The long neck of this dinosaur allows it to reach as high as the treetops as well as all the way to the ground. Part of its diet may consist of bracken ferns, which can be poisonous if consumed in large quantities.

In captivity, some Brachiosaurus have been known to eat watermelon and other fruits and vegetables. Artwork in the Jurassic Park Visitors’ Centre appears to depict a sauropod feeding on aquatic plants, but this has never been observed in life and is likely based on outdated hypotheses. Brachiosaurus will bathe in shoulder-deep water, but cannot survive in an aquatic environment.

Jurassic World: Evolution demonstrates its favored food to be tree ferns; it will also eat conifers and ginkgoes. However, it has difficulty digesting pawpaws, mosses, and horsetails, and may suffer deleterious health effects from eating these.

Social Behavior

While earlier reports from InGen’s IntraNet website indicated that this animal was solitary, further observations have proven this incorrect. In fact, the Brachiosaurus is a highly social animal, and simply is able to communicate over very long distances using its cries. As a result, a group of animals can spread out over a wide area and keep in touch, gathering back together to rest. This allows them to avoid overgrazing their territory. Animals of different sexes and age groups can be seen living together, with only minor squabbles over food when they are pressed for space.

Bathing in lakes and ponds helps these animals keep cool during midday and cleanse themselves to avoid infection.

Though they will peacefully live alongside any members of their species, they appear to prefer family groups somewhat like those of modern-day elephants. Animals with genetic relation can be seen staying close to one another, while herd members that are not related may ignore each other. A herd is led by a dominant individual (at least one alpha male has been reported), though how the alpha is determined is currently unknown.

In the game Jurassic World: Evolution, social groups of Brachiosaurus may contain up to five individuals, though they can live solitarily. A solitary brachiosaur was also reported in Survivor.


While breeding in Brachiosaurus is documented, the exact details of how they choose their mates and reproduce are still largely unknown. Presumably, the dominant males would have first mating rights, and likely use the colors of their nasal domes and resonance of their songs to attract females; in the Jurassic Park junior novelization, Dr. Alan Grant notes that the brachiosaur songs sound like mating calls, but as no male brachiosaurs were present on Isla Nublar at the time, standard reproductive behaviors would probably not have occurred. Same-sex pairing among brachiosaurs is far from impossible, but have not been witnessed explicitly.

All dinosaurs lay eggs to reproduce. Sauropod eggs tend to be rather large and round; fossil evidence suggests they are laid in large numbers. Most dinosaurs, like modern birds, have cloacae that house their reproductive organs, and presumably Brachiosaurus does as well. According to Jurassic Intel’s Guide to Dinosaur Eggs, the eggs of larger dinosaurs incubate for around a year.

Younger brachiosaurs, as they approach adolescence, can be highly independent and curious about their environments. At this age, they will test their surroundings to determine what is food and what hazards to avoid. Juveniles and adolescents usually remain near the adults for safety from predators, but thrive best in the company of their own age group. Even an age difference of one or two years may be enough to deter different brachiosaurs from engaging in play behavior together, and non-breeding adults do not provide any form of surrogate parent care. This leaves orphaned younger brachiosaurs vulnerable to the dangers of their environment, suggesting that a parent-offspring relationship is vital to their survival in the wild.

Brachiosaurus head study by Jama Jurabaev. The blue coloration on the face may appear later in life, suggesting that it advertises maturity.

Further evidence that brachiosaurs do provide parental care comes from the Hammond Creation Laboratory. In 2004, InGen scientists discovered that certain dinosaur embryos and hatchlings respond positively to different genres of music; Brachiosaurus appears to derive comfort from classical music. This was hypothesized to be due to the music simulating the heartbeat of an adult standing near the nest.

In the InGen IntraNet website, Brachiosaurus is said to be difficult to breed in captivity, with the animals showing little interest in mating. However, internal documents from InGen Security’s internal database describes the Head of Security Jim Boutcher using neurotoxins to poison the brachiosaurs due to their being a massive expense for InGen with low tourism appeal. While the extent to which this was actually carried out in the film canon is unknown, there is no evidence that Vic Hoskins (Head of Security 2001-2015) performed any similar operation.

Fossil evidence suggests that brachiosaurs reach sexual maturity when they are 40% of their adult size, significantly before they reach skeletal maturity. InGen research in 2004 demonstrated that while brachiosaurs of differing age groups will coexist, they really only socialize with animals within their own age group. An age difference of even a year or two may discourage adolescent brachiosaurs from socializing. This may be an adaptation to ensure that adult-sized brachiosaurs have no desire to mate with those that are still growing, as this would be extremely dangerous to the smaller animals.


Brachiosaurus communicate using a variety of loud wailing, hooting, trumpeting, and moaning sounds. Their calls are fairly simple, mainly being used to communicate over distance. They can be heard calling to one another while spread out feeding over an area, keeping in touch by broadcasting their locations. A brachiosaur’s cry can carry for up to ten miles, so within an area as small as Isla Nublar or western Isla Sorna, one animal would be able to communicate with most of the others from any location.

Juveniles have been said to make burbling sounds during play or when satisfied.

Ecological Interactions
Artwork of three Brachiosaurus in eastern Isla Nublar. The nearby Carnotaurus are no cause for alarm, as the brachiosaurs’ size keeps them safe. Image from the Dinosaur Protection Group.

By the time it reaches its adult size, a Brachiosaurus has no natural predators. A 1994 InGen report documented this animal successfully fending off a mature and healthy Tyrannosaurus rex. On Isla Sorna, they lived alongside both of the island’s apex predators, Tyrannosaurus and Spinosaurus, as well as smaller carnivores including Velociraptor, Compsognathus, and Ceratosaurus. The size of the adults protected them from being preyed upon, but juveniles and subadults may have been vulnerable to attack. On Isla Nublar, other carnivores existed in their habitat from late 2015 onward, such as Teratophoneus, Carnotaurus, and Allosaurus as well as the fish-eating pterosaurs Pteranodon and Dimorphodon. As there were no juveniles or subadults known on the island at that time, none of the brachiosaurs were vulnerable to predators. However, a dead adult brachiosaur would provide vast amounts of meat to scavenging carnivores in its environment.

The size of Brachiosaurus does not only protect itself from danger, but provides smaller animals with safety as well. These huge sauropods are frequently seen alongside other creatures. Hadrosaurs such as Parasaurolophus and Corythosaurus often appear alongside brachiosaur herds, and small birds also take shelter among them. Other modern fauna such as monkeys, sloths, lizards, and snakes can be found in the forested areas where brachiosaurs live. Armored dinosaurs such as Triceratops, Sinoceratops, Stegosaurus, Ankylosaurus, and Peloroplites are also known from brachiosaur territory, though Triceratops have been known to show aggression toward juveniles. Other dinosaurs seen in their ranges include Stygimoloch and Gallimimus.

Brachiosaurus has been observed alongside fellow herbivore Apatosaurus, but not the longer Mamenchisaurus. In fact, some competitive exclusion between Brachiosaurus and Mamenchisaurus was observed on Isla Sorna; the former was only known in the western island, while the latter inhabited the east. On the other hand, Brachiosaurus and Apatosaurus inhabited the same regions of northern Isla Nublar without issue. This is likely due to niche partitioning; Brachiosaurus feeds mainly on the upper branches of trees, while Apatosaurus feeds largely on the middle branches and undergrowth. Eric Kirby’s Survivor suggests that, on Isla Sorna, Diplodocus existed in the same territory as Brachiosaurus in a similar manner. All three of these sauropod genera are known to have coexisted in the Jurassic period, feeding on different food sources to avoid competing with one another. Brachiosaurus and Apatosaurus even make similar sounds, raising the possibility of interspecies communication. The game Jurassic Park: Operation Genesis states that it prefers to live alongside Camarasaurus as well, though this species has not been cloned in the film canon.

Such a huge animal supports a considerable microbiome. Digestion of all the plant matter it eats is accomplished through hindgut fermentation, which requires the help of many species of microorganisms. As InGen would probably not have been able to clone these microorganisms with precision, Brachiosaurus may have acquired modern species to fulfill this role. It is vulnerable to bacterial infections such as bumblefoot, which it regularly bathes to prevent, as well as viral diseases including the common cold. External parasites such as blood-drinking insects related to mosquitoes affected it during prehistory, and likely still affect the animals today.

A brachiosaur carcass would provide enormous amounts of meat to scavenging animals, similarly to whale falls in the ocean.

The copious amounts of dung it produces can act as fertilizer for local plant life, so while the brachiosaur can clear away forests of trees, it also provides nutrients to other plants. It is known to feed on the invasive Moreton Bay fig and its epiphytes, which would be beneficial to Isla Nublar’s native ecosystem. It also preys on low-nutrient plants such as palm trees and eucalyptus, which other animals likely would not feed on, and the introduced monkey puzzle tree (Araucaria araucana).

In the game Jurassic World: Evolution, most sauropods including Brachiosaurus are incorrectly portrayed as being immune to the common cold. This dinosaur has been directly observed suffering from a cold, and the Dinosaur Protection Group confirms that infections in this dinosaur are still known.

Interactions with Humans

A gentle creature in spite of its enormous muscular bulk, the Brachiosaurus has a mostly peaceful relationship with humans in its environment. It was among the first dinosaurs to be successfully cloned by InGen, and was one of the major attractions to the original Park. Two separate paddocks were constructed to house the creatures, which lived alongside Parasaurolophus; the primary paddock could be viewed from the main tour road while the second was visible from a service road used to bring VIP guests and staff in from the helipad. While InGen CEO at the time John P. Hammond was very fond of the brachiosaurs and the Park’s endorsement tour was very impressed by them, the animals would have been a major expense, eating hundreds of pounds of food every day. While the extent of its relevance in the film canon is unconfirmed, the InGen IntraNet website describes the brachiosaurs as a burden to InGen; their upkeep was highly expensive and their low activity levels aside from eating reduced their tourism appeal. Hammond had considered shipping them to poorer countries as a source of meat, but found the expenses too great. He was opposed to euthanizing any of the dinosaurs, which led to Head of Security Jim Boutcher doing so clandestinely without the knowledge of his superiors in Operation Clean Sweep.

Brachiosaurus continued to be a troubled species when Jurassic World was constructed. The few that remained on Isla Nublar were temporarily relocated to Isla Sorna in 2002 and then returned to the island between January 2004 and May 2005. Reintroducing the animals was a massive undertaking and one of the major functions of the Masrani Global Corporation internship programs of 2004. The January-May internship program oversaw the introduction of two older brachiosaurs, Olive and Agnes, who had been present in the original Park. Attending to their health and wellbeing was paramount as they were reintroduced to Isla Nublar, where they would reside in the central valley and exhibited in the gyrosphere attraction. They were affected by health issues, particularly a highly acidic mutant strain of indigenous cyanobacteria.

During the second internship, the Bright Minds program, interns oversaw the introduction of more species to the valley, but still provided care for the Brachiosaurus. By this time, two juveniles named Pearl and Dot had been introduced to the island. The adolescent Pearl was a particular source of concern, as she lacked parental guardians and was highly energetic. This meant that she needed more attention from her caretakers than other dinosaurs. She frequently used empty gyrospheres as playthings; InGen’s ACU division recommended isolating her in a separate habitat to avoid damage to property. However, several of the Bright Minds interns were able to develop toys to keep Pearl stimulated, allowing her to remain within the valley.

Adult female Brachiosaurus feeding on eucalyptus, Isla Nublar (6/11/1993)

Prior to 2014, the brachiosaurs were relocated out of the valley into Sector 5 in preparation for a new attraction, Treetop Gazers, which would have allowed visitors to view the brachiosaurs much more personally than the gyrospheres permitted. Unfortunately, Jurassic World closed in late 2015, so this attraction was never completed.

Brachiosaurus are often stereotyped as dull and unintelligent, like many herbivorous animals. Direct observation, though, has demonstrated that they are actually curious, sociable, and can become affectionate. They can be trained to respond to basic commands using clicker devices and food rewards.

Much research into brachiosaur intelligence took place during 2004, with a six-year-old female named Pearl being studied by a group of interns from the Bright Minds program including future Jurassic World Senior Assets Manager and Operations Manager Claire Dearing. The program found that certain patterns and colors would stimulate the regions of her brain associated with pleasure; spots and hexagons were the most effective patterns, while red and orange were the most effective colors. It was hypothesized that these features were the most stimulating because they differed visually from food or terrain. Pearl was also excited by particular sounds, but would not play with gyrospheres that still had occupants. She was very affectionate toward her caretakers, though older adults were more accustomed to human contact. Still, even adults can be curious of human activity and will sometimes approach humans to investigate them. Some brachiosaurs appear to recognize humans as caretakers after a lifetime in captivity and may seek them out for help when they are frightened or distressed.

Brachiosaur dung was used as fertilizer by Masrani Global Corporation in their research greenhouse, which housed modern and de-extinct plants as well as experimental hybrids. The manure was held for a period of six months before use. It is likely that, once the public greenhouse and research greenhouse were merged with the arboretum to form the Botanical Gardens, manure from dinosaurs such as Brachiosaurus was still used for this purpose.

Between 2017 and 2018, the Dinosaur Protection Group sometimes used imagery of Brachiosaurus to attract public support for the planned rescue mission to Isla Nublar. While the rescue mission as they intended never occurred, at least one adult Brachiosaurus was removed from Isla Nublar by a mercenary team hired by Eli Mills. The animal was intended to be sold at auction on June 24, but as the auction was disrupted, it was instead released into the forests of the Pacific coast. During the escape, the brachiosaur caused considerable damage to parked vehicles and came close to crushing Mills, but no brachiosaurs have ever been confirmed to intentionally kill or harm humans. Their size means that they could easily cause serious harm by accident during play or simply by not noticing a human, however.

Based on Jurassic World: Evolution, the cost for raising a Brachiosaurus from fertilization to maturity as of 2018 would be $784,000.

Behind the Scenes

Brachiosaurus was selected to be featured in Jurassic Park due to its unusual physiology, which Industrial Light & Magic animator Phil Tippett considered to be more of an interesting challenge than the Apatosaurus which appeared in the original novel. The brachiosaur scene in the first film has often been cited as a turning point in digital animation, and was ranked 27th in an Empire Magazine listing of most magical movie moments. It has influenced other film franchises as well; in the 1997 re-release of Star Wars Episode IV: A New Hope, the Brachiosaurus CGI model was modified to create a creature called a “ronto” which appears in the film. The name of the ronto is derived from “bronto,” as in Brontosaurus, with which Brachiosaurus is sometimes confused. Similarly, the Brachiosaurus CGI model was reused and modified in The Lost World: Jurassic Park to create the Mamenchisaurus.

The species referenced for the appearance of Jurassic Park‘s Brachiosaurus has since been reclassified as a species of Giraffatitan. However, since 1997, promotional material for the films has largely treated the animal as Brachiosaurus altithorax, with the mobile game Jurassic World Alive even including Giraffatitan as a separate dinosaur.