The dinosaurs listed in this page are among the most unusual and bird-like of Isla Sorna’s dinosaur population. All exhibit bird-like behaviour and are feathered (with the exception of Gallimimus), however none of these dinosaurs are capable of flight. In addition, despite being theropods (the group of dinosaurs which include predatory forms such as Velociraptor and Tyrannosaurus) these dinosaurs are typically omnivorous or, in the case of Erlikosaurus, completely vegetarian.

Avimimus portentosusEdit

Length: 5 ft (1.3 m)

Height: 2.5 ft ( 0.8 m) at the hips, perhaps 3 ft (0.9 m) at the top of the head

Weight: 50 lb (22.7 kg)

Avimimus is a small, delicate, bird-like dinosaur related to Oviraptor. Like Oviraptor, Avimimus lacks teeth (instead sporting a parrot-like beak), has a light body and long legs, a long neck and a small head, and is feathered. Avimimus are omnivorous- they consume plant and fruit matter as well as invertebrates and other small animals, such as rodents and lizards. The prey is swallowed whole with a bird-like motion of the head. The Avimimus also has the unique ability to mimic sounds from all around them, similarly to a modern lyre bird. These sounds can include other dinosaur calls, bird calls, and non-animal calls such as falling trees and running water. The male uses a mixture of these sounds along with its own calls to attract females. While females are equally capable of mimicry, they are not as often heard as the males.

Avimimus’ preferred habitat is anywhere with sufficient cover to hide from predators and to build their nests. Such locations include in thickets, rock piles, or other hard-to-access places where predators would have difficulty reaching or even finding. When faced with a predator, an Avimimus’ only defence is to run.

Avimimus live in pairs which mate for life. Couples engage in neck-rubbing and cooing to strengthen their bonds, and both parents will play an active role in rearing their young.

Avimimus tends to be nocturnal, and its eyes are large to allow it to see clearly in the dark.

Coloration and Sexual DifferencesEdit

Males have pure white feathers with a series of sky-blue bands running lengthwise along their sides. Females have light grey feathers with a series of greenish yellow bands running lengthwise along their sides. The juveniles of both sexes are the same as the female.

Erlikosaurus andrewsiEdit

Length: 20 ft (6.1 m)

Height: 15 ft (4.6 m)

Weight: 1.5 tons

Erlikosaurus is a theropod (which are usually carnivorous or omnivorous dinosaurs), although instead of meat, an Erlikosaur’s diet consists only of plant and root matter. Erlikosaurus is bipedal, has a plump body and a relatively short tail, and a small head perched on a long, slender neck. The jaws are beaked with small teeth at the back of the mouth, and the tongue is quite long and flexible, used to wrap around plants. One of the most striking features of this odd-looking dinosaur are its fierce-looking claws, which can reach up to three feet in length. Despite their dangerous appearance, these claws are generally used to shear off branches of food which it then shoves into its small beaked jaws, or to pull branches towards its mouth. However, when faced with a predator such as Tyrannosaurus, the claws make lethal weapons.

Erlikosaurs are peaceful and slow-moving. They tend to be solitary, although they have been known to tag along with different species of herbivorous dinosaurs for short periods of time. When threatened, Erlikosaurs will shriek and face a predator while stretching out its long arms- this not only makes the animal look larger than it really is but also fully displays the vicious claws.

Erlikosaurus inhabit upland regions, such as the Southern Highlands and San Feredano Mountain Ranges, which they often migrate between. Erlikosaurs make loud and distinctive squawks, which echo through the highland altitudes in which they live.

Coloration and Sexual DifferencesEdit

Males have long bright blue feathers running down their back with creamy scales on their head, neck, underbelly and legs. Females are similar to the male, however they have dark purple feathers rather than bright blue. The juveniles of both sexes are covered in feathery, brown fluff.

Gallimimus bullatusEdit

Length: 13 ft (4 m)

Height: 9 ft (2.7 m)

Weight: 1,000 lb (453.6 kg)

Gallimimus is a small, fleet-footed dinosaur most commonly found living in huge flocks of 30-50 individuals on the Game Trail, where they mingle with larger herbivores such as hadrosaurs and ceratopsians. Gallis are nervous and are always on the lookout for danger- their senses are highly acute and they often detect predators before other dinosaurs- producing a brief, high-pitched scream as a warning call. Thus many different species of herbivorous dinosaur tolerates the Gallis’ presense, benefiting from the extra lookouts and early warning systems.

A Galli is relatively defenceless against predators (however they can give a powerful kick with their sharply-clawed hind legs, which may stun a small predator long enough for the Galli to escape), however its tendency to live alongside others of their kind and other herbivorous dinosaurs gives it the advantage of spotting danger early, before fleeing at an incredible pace. Gallis are easily spooked- a sudden movement from even a non-dangerous animal could potentially cause the entire flock to stampede. Gallis can run at speeds of up to 55-60 mph.

Although generally classed as a herbivore, Gallimimus is in fact omnivorous, feeding on plants, fruit, eggs, and small animals such as insects and lizards. During the breeding season, males fight over females by kicking at one another with their hind legs.

Gallis do migrate alongside other dinosaurs to the nesting grounds- however not just to lay their own eggs. Gallis will also attempt to steal the eggs of other dinosaurs, although only when the parents’ backs are turned.

Coloration and sexual differencesEdit

Males are shades of orange, with some individuals having striping or blotches. Females are like the males, although females are usually a paler orange, with some individuals having striping or blotches. The juveniles of both sexes are the same as the female.

Oviraptor philoceratopsEdit

Length: 10 ft (3 m)

Height: 4.5 ft (1.4 m)

Weight: 80 lb (36.3 kg)

Among the strangest-looking dinosaurs on Isla Sorna (along with Erlikosaurus), Oviraptor resembles a large bird- on the top of its head there is a crest similar to that of a cassowary. Oviraptor has a powerful beak and no teeth- however there are a pair of bony prongs on its upper palate. The dinosaur uses its “nut cracking” jaws to crack open hard-shelled food objects such as nuts and eggs to eat the contents. This dinosaur also consumes carrion, invertebrates, lizards, small mammals, and dinosaur chicks- even the young of dangerous predators such as Velociraptor are taken. Oviraptor grasps food items with its three fingered, sharply-clawed hands. It usually snatches chicks and eggs before running off at high speeds in order to escape an angry parent.

Oviraptor’s preferred habitat is dense forest and the thick jungle areas where it is safe from larger predators- however during twilight hours it may venture out onto the Game Trail in order to visit the nesting grounds of hadrosaurs and ceratopsians , where it will steal eggs and nestlings under the cover of darkness.

Oviraptors are solitary until they find suitable mates. A male will attempt to impress a female by performing a mating dance similar to a crane- shaking feathers, running around and hopping into the air. If a female is satisfied with the male, they will remain together for life, and other Oviraptors will not be tolerated within their territory.

Despite the Oviraptor being an egg-thief, parent Oviraptors are particularly protective over their own eggs. Both parents contribute to rearing the young, with either one sitting on the nest (the eggs hatch quicker than other dinosaur eggs because of the Oviraptor’s feathers help incubate them more efficiently than vegetation) while the other gathers food or keeps watch for danger. Usually the nests are well-hidden, however if a predator detects the nest, one parent (usually the male) will attempt to divert the predators’ attention away while the female will lead her young to safety.

Oviraptors are intelligent and curious and not considered aggressive, however they can deliver a powerful bite.

Coloration and sexual differencesEdit

Males have creamy orange scales with long black and white feathers on the arms, neck, back and tail, with a red crest. Females have brown and white feathers and an orange crest. Juveniles have a creamy orange body with brown blotches and no feathers.