These herbivorous dinosaurs are also known as “duck-billed dinosaurs”, due to the similarities between their heads to those of ducks. The front of the mouth of Hadrosaurs is a wide, flat beak, used to snip vegetation.

There are two types of Hadrosaur- ones with elaborate crests on their heads (Lambeosaurines), and ones without (Hadrosaurines). The crested species can be distinguished by the shape of the crest- for example, the crest of Parasaurolophus is long and tubular, protruding from the back of the head, while the crest of Corythosaurus resembles a helmet, and the Lambeosaurus’ crest is shaped like a hatchet. These crests allow Hadrosaurs to produce calls unique to the species. The Hadrosaurs which lack crests are nonetheless just as vocal- producing loud, nasal bellows used both for communication (keeping the herd together) and to warn others of approaching danger. Hadrosaurs are among the noisiest of dinosaurs on Isla Sorna. Multiple species herds are known to sound like an orchestra.

What separate these dinosaurs from other herbivores are their advanced chewing mechanisms- Hadrosaurs have a highly-specialized method of feeding, which first allowed these dinosaurs to become so successful during their original timelines. The teeth of Hadrosaurids form “batteries” made out of literally thousands of self-replacing teeth used to grind food, allowing them to feed on a far wider selection of vegetation than other herbivorous dinosaurs on Isla Sorna.

Hadrosaurids are the principle prey of large carnivorous dinosaurs such as Tyrannosaurus; yet they have no weapons to defend themselves apart from their size. Therefore Hadrosaur senses are very sharp and they are constantly on the alert for danger. They also rely on living in herds for protection and are seldom seen alone. Hadrosaurs are naturally shy and gentle animals, however stampeding herds are dangerous. They are mostly quadrupedal; however they may rise up onto their hind legs to feed from higher levels. Hadrosaurs also tend to run on their hind legs, using their thick, heavy tail for balance.

Hadrosaurs are well known for their nesting behaviour- they are particularly attentive parents which care and look after their young until they leave the nest and can travel with the herd. (More information on Hadrosaur nesting behaviour found under Maiasaura).
Hadrosaurs are generally harmless, only showing dangerous behaviour if they are panicked.

Anatotitan copei Edit

Length: 40 feet

Height: 14 feet
Weight: 5 tons

Anatotitan, image done by T-PEKC

This is a non-crested species, and the largest species of Hadrosaur on Isla Sorna. Anatotitan are naturally peaceful animals, and while seemingly defenseless, the Anatotitan’s large size means that even a single adult animal is capable of trampling smaller predators, such as raptors and dilophosaurs- and when they stampede en masse, even a Tyrannosaur would be wise to get out of their way. The Anatotitan will prefer to flee as its primary defense- it can run up to 35mph on its hind legs.

The Anatotitan’s preferred habitat is wide open spaces broken by brush. It is not fussy and consumes any type of vegetation- grabbing large mouthfuls of multiple types of plant life at once with its wide beak and chewing it to a pulp with its batteries of grinding teeth.

Anatotitan does not have a crest, but it amplifies its calls with inflatable sacs on its snout area.

As with all Hadrosaurs, Anatotitan are very protective of their young.

Coloration and Sexual differences

Males have brown bodies and pale underbellies, with intermediate purple blotching and a red snout. Females are like the male, although lacking in the purple and the red snout. The juvenile of both sexes are very light brown, which gets darker through to adulthood.

Corythosaurus casuarius Edit

Length: 30 feet
Height: 20 feet
Weight: 3 tons

Corythosaurus, image done by Hellraptor

Corythosaurus is easily recognized by its laterally-flattened, plate shaped crest. This crest is larger and rounder in males. As well as being used for gender recognition, the crest also helps the Corythosaurus to produce calls different from any other type of duckbill. The sounds a Corythosaurus makes are loud, short, high-pitched cries.

Like Parasaurolophus, Corythosaurus is a peaceful and easily-scared animal. When facing danger it usually flees- running quickly on its hind legs- however if cornered, its large size and powerful tail and legs can be very dangerous weapons against smaller predators. Like most Hadrosaurs, large numbers of Corythosaurus stampede- this makes it difficult for a predator to pick out a single individual and therefore may be forced to abandon the hunt to prevent the risk of being trampled.

Corythosaurus live in herds and often join herds of other duckbilled dinosaurs such as Parasaurolophus. As with all Hadrosaurs, Corythosaurus have very acute senses- especially eyesight and smell. Although they usually graze on all fours, they often stand on their hind legs to observe their surroundings.

Corythosaurus live in open plains dotted with trees, where they feed on a wide variety of vegetation. They can often be found herding with Anatotitan and Parasaurolophus.

Coloration and Sexual differences Edit

Males have a creamy white body, with orange splotches outlined in black and a vivid red crest. Females are the same, although they have a smaller crest. Juveniles of both sexes are as the adults, however they lack crests at birth.

Hadrosaurus foulkii Edit

Length: 28 feet
Height: 7 feet
Weight: 3 tons

Hardosaurus, image done by T-PEKC

This non-crested species prefers more heavily-wooded terrain than most other Hadrosaurs, but they will make do with more open terrain if food is plentiful enough. Their preferred food

types are shrubs and saplings, and they live in small, loose-herds.

In a Hadrosaurus herd, it is the females which dominate over the males. During the mating season, female emit an ear-splitting yowling sound to attract males, which are then forced to watch as the females engage in mock charges and tail slapping with other females.

Coloration and Sexual differences Edit

Males, females and juveniles have brown mottled bodies with pale yellow underbellies.

Lambeosaurus lambei Edit

Length: 31 feet
Height: 13 feet
Weight: 5.2 tons

These Hadrosaurs can be found in the bayou-like cypress swamps of the East Delta, where they feed on cypress leaves and a variety of other plant species which grow in the Lambeo’s swampy habitat.

Lambeosaurus’ hatchet-shaped crests are distinctive, even amongst Hadrosaurs. They utilize infrasound calls to keep in contact with Lambeosaurs scattered across the various pockets of cypress swamps, in addition to their more audible calls when within range of other Lambeos.

Lambeos are less social than their grassland and forest-dwelling relatives. They generally stay alone as the small pockets of cypress swamps can support only a few Lambeos each, however individuals keep in contact with all other Lambeosaurus on the island through long-distance infrasound calls.

Coloration and Sexual differences Edit

Both sexes of adults and juveniles have dark brown scales with white stripes on their backs. The males' crests are larger than than those of the females, and newely-hatched young lack crests altogether.

Maiasaura peeblesorum Edit

Length: 30 feet
Height: 13 feet
Weight: 4 tons

Although these Hadrosaurs are categorized as being “non-crested”, Maiasaurs do in fact have a small pointed crest above the eyes. Like all Hadrosaurs, Maiasaura are nervous, constantly on the alert for danger, and they live in herds which often stampede as a defense mechanism.

Maiasaura are well-known to have been caring parents- their very name means “good mother lizard”. This is also true for Isla Sorna’s Maiasaura population, however it also implies to all other Hadrosaur species on the island.


Maiasaura, male and female, image done by T-PEKC.

During the breeding season, multiple species of Hadrosaur (including Maiasaura itself) will migrate- often for long distances- to the Nesting Grounds- an area nestled between the Jungle and the Game Trail- in order to raise their young. The Hadrosaurs stick together and nest in huge colonies, with the nests situated several metres apart to allow the parent animals to move about. It is often very difficult to separate a parent from their nest- small egg raiders are often shooed away by a bellow or a warning snap of the beak, but if the parent is killed by a larger predator, their nestlings will most likely starve. Older individuals which have already left the nest may be adopted by another member of the herd.

The Maiasaura’s nesting and child-rearing behavior is even more refined than even the other Hadrosaurs. Maiasaurs stick close to their own kind and all pitch in to guard one another’s nest while other individuals take turns to feed. The eggs are carefully incubated with vegetation, and the helpless hatchlings remain in the nest while the adults protect them and bring them food. After four or five months, the offspring are old enough to travel with the rest of the herd. Even in a large family herd, the young can recognize their own parents by the pitch of their calls.

Maiasaura are most commonly found in the conifer forests at the south end of the island, although they can be found elsewhere. They prefer to eat conifer needles and cones if they can find them.

Coloration and Sexual differences Edit

Males have yellow bodies with a horizontal orange stripe across their flanks and an orange back. Females are a beige color with some light orange mottling. The juveniles of both sexes are the same as the female.

Parasaurolophus walkeri Edit

Length: 30 feet
Height: 13 feet
Weight: 3 tons

Parasaurolophus, image done by Hellraptor

Parasaurolophus is one of the most distinctive dinosaurs, due to its spectacular tube-shaped crest up to two meters long. This crest allows the dinosaur to produce a loud trombone-like sound, which is produced constantly by the herd in order to reassure and keep individuals close. Calls warning of danger are somewhat louder and higher in pitch. Aggressivity is almost unexistant among these Hadrosaurs, as conflicts are solved quickly by size exhibitions and deafening sound contests.

Parasaurolophus are known to be among the most sociable of herbivorous dinosaurs on the island, living in large herds. It often intermixes with herds of Corythosaurus and numerous other herbivore types, such as Gallimimus. Some Parasaurolophus herds have even formed symbiotic partnerships with groups of Brachiosaurus. The Paras, with their sharper eyesight, help to keep on the lookout for predators, while the Brachiosaurs repay their smaller companions by protecting them with their immense size and strength. When attacked, Parasaurolophus herds stampede. Predators may decide to abandon the hunt if the risk of being trampled is too great.

The Parasaurolophus’ batteries of grinding teeth can handle practically all vegetation on the island, so they’ll eat any plant matter that they come in contact with. They inhabit wide open spaces, preferably with a nearby water source.

Coloration and Sexual differences Edit

Males normally have a brown and orange mottled body with a red crest. In the mating season, they turn to a green and brown mottling. Females have green mottling, with some individuals having blue blotches and stripes. Juvenile males are the same as the non-breeding adult male, and juvenile females are the same as the adult female, although more yellow in appearance. The young lack crests at birth.