Brontosaurus excelsus

Coloration:
Adult (both sexes) - A gray color with darker gray markings on the back.

Juvenile (both sexes) - Lighter gray body.

Diet:
Low to medium-high growing plants.

Preferred Habitat:
Wide open spaces to accommodate its size.

Social Structure:
Medium-sized groups close to hadrosaur herds and other sauropod species.

Description:
Giant quadrupedal herbivore. A long-necked sauropod, Brontosaurus is the third largest animal on the island. It is a heavily-built animal with forelimbs slightly longer than its hind legs, a small head in comparison to its body-size, and jaws lined with chisel-like teeth. The whip-like tail is long and tapered at the end, held clear off the ground. The long neck is relatively stiff and cannot be lifted much higher than shoulder height.

Behaviors:
Brontosaurus' tail has multiple functions. Its primary use is to counterbalance the animal’s long neck. Most famously, it is used as a weapon against predators. However, the tail is also used as an important communication device between other Brontosaurus. In a herd, members keep in constant contact with others in the group with their long tails; occasionally whip-cracking and using the resulting breaking of the sound barrier to communicate over long distances. The tail also serves as a visual communicator; with individuals constantly waving their tails in the air to remind others of their location, thus helping to keep the herd together. In addition, Brontosaurus touch the backs of other individuals at close range with their tail tips almost continuously, particularly youngsters, seemingly to reassure and comfort others with their presence.

The tails of male Brontosaurus are used as a device to attract females. During the breeding season, males can be easily distinguished by the ends of their tails, which develop red rings as they become flushed with blood. Males will wave their tails around in front of a receptive female, accompanied by deep-frequency bellows and stamping of   their feet. Competing males will attempt to warn the other off using this method as well, although in extreme circumstances fights may break out, involving each male standing side by side and attempting to use their bulk to push and shove against one another in tests of strength.

Brontosaurus females lay their eggs en mass on the edges of forests. The females will then quickly move away, being far too large to remain without risking stepping on the vulnerable eggs and young. A few of adults may remain nearby, discouraging predators from approaching. Although hundreds or even thousands of eggs may be laid between the three sauropod species, few survive to hatch and even fewer hatchlings survive into reach their full size owing to the abundance of predators on Sorna. Like baby turtles, the sauropodlets will instinctively make a  beeline for the relative safety of the forests, remaining together in  mixed species crèches. Juveniles grow rapidly, and upon reaching adolescence they will move out of the forests onto the open grasslands in order to seek adult herds to join.

Even though the full-grown adults have little to fear against predators due to their immense size, the younger individuals are vulnerable to predators such as Allosaurus. The young remain in the center of the herd while the much larger, older individuals remain on the outside - providing a barrier to hide and protect the vulnerable juveniles from predators. The adults may be preyed on by Giganotosaurus, and they protect themselves by lashing out with their whip-like tails, inflicting painful, discouraging blows. Brontosaurus produce distinctive bellowing and whinnying calls. Herds are often followed by packs of Allosaurus and Giganotosaurus.