Jubaeibatus

Jubaeibatus genesis "origin helmet-crest"

29-35 feet long

Jubaeibatus [helmet-crest] is the most common and numerous of the large-bodied herbivores to be found on Skull Island. Normally found in herds of several dozen or so, they graze on tree bark, fruit, grasses, leaves, roots, and water weeds. Thus, they are found in most of the ecological zones of Skull Island, from the wetlands to the jungles, and, in fact, are the only herbivores willing to take to the water to escape predators.

The Jubaeibatus is a vocal animal and communicates with other herd members via a variety of calls. Some calls are used to keep the herd together when moving through the dense jungle, others assure the herd all is well, some are used to call attention to a new food source, while others are used in domination disputes. Vocalizations, as well as changes in crest color, are used during the breeding season to attract females to the males. Sparring over females is common, and many males, tired and battered from fighting over the females, are taken by predators.

Jubaeibatus is an ornithischian dinosaur, with broad, three-toed feet, a long tail, and a duck-like snout. A horn-like protrusion at the back of the skull supports a large hatchet crest and a second long finlike crest. They move on two legs and four and use their tails to counterbalance their movements.

## facts

The most numerous large herbivores on Scar Island, *Jubaeibatus* congregates in herds numbering several dozen individuals. *Ligocristus* are hadrosaur ornithischians, with broad, three-toed feet and distinctive wide, duck-like snouts. With no other defenses, safety is found in numbers, where many eyes improve the chances of predators being spotted. Being strong swimmers, *Jubaeibatus* are also among the only native herbivores that will readily take to the water to escape land-based threats. Nonetheless, they are the staple prey species for many different predatory creatures from *D.rexes* to *Kynigosaurus* to *Payaradoselache* to *Fataliodon* and phorusrhacid species like *Barosornis* and *Zostropteryx*.

Mottled markings camouflage the *Jubaeibatus* when in the dappled light of the forest or the deeper jungle. In the open, their patterning helps break up their outlines. Being more shore-footed and agile than the great lumbering sauropods, *Jubaeibatus* are able to move with greater ease through the many different vegetation zones on the island, granting them access to a wide range of food sources. All-purpose feeders they can eat a variety of vegetation: grasses, leaves, water weeds, fruit, roots, and other plants even tree bark. They can browse at heights of up to 25 feet.

*Jubaeibatus* are highly vocal animals (typical for lambeosaurines). The valleys echo constantly with their trumpet-like vocalizations as they call to one another to maintain herd cohesiveness while moving through the dense and obscuring jungle and to reassure one another of safety when feeding in the open. Their vocabulary is surprisingly large, with a range of calls for different purposes. Soft rumbles made while eating signal the availability of different foods to each other and complex grunts are used to communicate social messages of dominance and mood between individuals.

## Breeding

Sporting prominent bony crests with long trailing flaps of skins, *Jubaeibatus* are able to communicate mood and breeding status visually. In a mechanism similar to that of a chameleon or a cephalopod, chromatophores in a *Jubaeibatus* crest skin flap can flush to create different hues on the skin as a result of hormonal signals. In the breeding season, males will signal dominance and sexual maturity with deep vermilion crest displays and bellows. Males excavate performance scratches in the earth and compete for female attention with posturing and loud calls. Territorial sparring matches over the best display positions are common. In the breeding season, exhausted competitors make easy pickings for wise predators.

## Skull Adaptations

*Jubaeibatus* skulls include several specialized features supporting their lifestyle. Highly vocal, they have enlarged resonating chambers in their skulls and crests, through which they are able to trumpet loud calls to one another.

Their broad snouts widen into hard, flat beaks, ideal for plucking and grinding a wide range of vegetation. Powerful muscles drive their strong jaws, which lack front teeth but are lined with low, hard molars at the back. Vegetable matter mashed between horny plates of the beak is passed back to be thoroughly pulverized and pulped before swallowing. A distinctive side-to-side chewing motion and the ability to store food in the cheeks lends these dinosaurs a distinctly cattle-like countenance as they quietly feed, perpetually chewing on their end.

## Eyes on the Horizon

As the main course for predators, *Jubaeibatus* herds are forced to maintain a constant lookout for danger. Eyes are positioned high on the head and angled outward to take in an almost 360-degree view. The pupils are horizontally slotted to concentrate vision along the horizon line. At their most vulnerable during low feeding, when their heads are down, their eyes are able to swivel, maintaining a horizontal bias regardless of the snout’s angle.

## Island Breeding Sanctuaries

Seeking to avoid predators and egg thieves, some *Jubaeibatus* mothers choose to nest on small islets and sandbars in the swamps that are exposed during the driest months. Away from predatory eyes, the nests are less likely to be raided. Few of Scar Island’s land-based predators are inclined to swim, and the river’s own resident carnivores are mostly water-bound.

Left to develop on their own, the small clutches of eggs will hatch in synchronized batches to maximize the chances of survival for the young. Calls of the hatchlings draw their parents back to the islands, where they will stay for several days until the young are strong enough to risk leaving the safety of the sanctuaries. The drone of mosquito wings maddens *Jubaeibatus* young in their island nurseries in the hot months when vast clouds of the vampiric insects rise out of the swamps to plague them, but with dragonflies and other predators, the mosquitoes are hunted.

For adults, the short swim across a river or through marshlands is no great hardship. For new hatchlings, however, this trip can be perilous. Several species of water predators (such as *Hudruscimex*, *Incolas*, *Martimosaurs*, and *Scar Island snappers*) make it their business to be waiting nearby when the adult *Jubaeibatus* return to guide their young back to land again after hatching.