The unchallenged master of the waterways of Skull Island is the gargantuan Piranhadon, scientifically named more for its carnivorous habits than for any resemblance to a true piranha. A titanic lobe-finned fish, it grows as large as some whales. Piranhadon is an ambush predator, mostly taking terrestrial prey that come to drink (only to find themselves dragged down to a watery doom). Though it will also hunt below the surface, the majority of a Piranhadon’s prey is taken from the bank or plucked from the surface while attempting a crossing.
Piranhadon eyes are large, but not terribly acute. Their vision is restricted to extremes of light and dark. Staring up, they will respond to shadows created against the bright light of the sky that indicates potential prey on or near the surface. Underwater prey is more difficult to discern in the murky water.
Their bodies have evolved to allow short bursts of high speed, as befitted an ambush predator, but will need to rest for long periods between attacks.Massive banks of gills supply the bony fish with oxygen from the water. Water that is heavily clogged with silt makes it difficult for the species to breathe, restricting its access to the river system. Piranhadon have elongated necks that are flexible so as to allow them to weave through the flooded forests and narrow waterways they hunt in spite of their great size. Side-to-side tail movement provides propulsion, while the massive paddle-like pectoral fins steer the animal with surprising agility. Streamlined and smooth, the great beast can move swiftly through the water, creating barely a ripple on the surface to betray its passage. The larger the individual, the faster it can swim.
Male Piranhadon are much smaller than the giant females, rarely exceeding 20 feet in length, and outnumber them several times over. During the mating season, the big females make no effort to accommodate the affections of their many tiny suitors. Only the strongest and fastest males can catch up with them and deposit their seed, thereby guaranteeing the best genes for their offspring.
Young are born live in groups of around a dozen. Fully five feet long at birth, they are already formidable aquatic predators and take to hunting in the shallows right away. Here they perfect their ambushing techniques on water birds and small non-avian dinosaurs. Juvenile Foetodon are common prey, snapped up as they float on the surface in their nursery groups.Plagued by many assorted parasites, one of the most unconventional behaviors exhibited by Piranhadon is voluntary beaching. Selecting an appropriate beach that provides sufficient slipway for returning to the water, the fish will swim at speed up and onto the shore. Several bird species (like herons and gulls) know this behavior and will fly down to meticulously clean the aquatic predator of its unwanted passengers alongside two small lizard species. Despite the usual danger the predatory bony fish presents, while being groomed and attended it is no threat, willingly permitting enterprising cleaner birds (as well as a few small reptiles) to pick parasites and other food from between its mighty jaws. The bony fish can stay ashore for only a short time before suffocation and heat compels it to submerge. Using its huge pectoral fins to heave itself, a Piranhadon flexes and arches like a gigantic seal, sliding back into its natural habitat.
Surprise AttackDespite the serenity of the waters, Skull Island’s rivers and pools are at least as dangerous as the jungle. The deceptively serene waters hide a menagerie of terrifying creatures, among them, the nightmarish predator Piranhadon.
Piranhadon hunts sections of rivers’ edges that slope steeply, permitting it to lurk very close to the beach while still remaining hidden beneath the surface. Lying along the bottom, the lobe-finned fish’s two enlarged and sensitive barbels pick up footfall vibrations through the ground that will signal the approach of potential terrestrial prey. Drawn to the bank to drink, land animals (such as Ligocristus and Hylaeornis) cast telltale silhouettes across the water’s surface as they come within range of the piscine predator’s strike.
A sweep of its mighty tail will send the Piranhadon surging forward, its huge, gaping head propelling out of the water to grab the unfortunate victim. Often the prey will be lifted high into the air to crash down violently again into the boiling water, firmly trapped between the bony fish’s gin trap jaws. If still alive after the impact of the attack, prey is dragged struggling beneath the surface to be drowned and swallowed whole.