River Dragon

Widespread and adaptable, river dragons are the descendants of the migratory sea dragon, a widespread marine predator that was able to move freely between fresh and saltwater habitats. As the ice age melted and produced raging rivers of meltwater that led to the sea, these giant eelsnakes traveled up along them and found new prey in the abundant thorngrazer herds that spread out across the thawed plains in incredible number. While this species lives in the northern hemisphere, similar forms are found across the world in the early hothouse, 275 million years post-establishment. 

Five million years have now passed since the great thaw, and in Serinarcta the former sea dragons have adapted perfectly to a life in freshwater as one of the apex predators of the soglands. They can move out of water just as their predecessors could with snake-like undulations aided by their claw-like pectoral fins, but no longer need to bask to maintain body heat, and usually only do so at night to reach other isolated water bodies. Darker bodies and bolder markings camouflage in murky, vegetated water while a longer and narrower body can slip easier through the grass. They have gotten much longer, as long as 25 feet in exceptional cases, but thinner too, so that they are only about 30% heavier, reaching weights of about 1,000 pounds at their extreme. Though they may sometimes be found to hunt alone, they are usually pack-hunters with surprising social behavior, living in clans of five to as many as twenty with a dominance hierarchy based on size. River dragons are intelligent and very active; they cooperate as a group to bring down large prey that is ambushed as it crosses shallow water; a bite force of 4,500 lbs per square inch is sufficient to hold tight onto even the largest of thorngrazers's legs, and a large enough group pulling in tandem can drown even a monstroctorn, one of the only animals that can regularly kill such a large and formidable creature. River dragons travel in their packs in very close formation, their eel-like forms siding up alongside each other and swimming between one another, resembling a single much larger animal when viewed in the muddy water from above, which discourages anything else from harassing them and protects their offspring.

Packs of river dragons are usually based around peers of similar age, but adult packs also include juveniles under a year old under the care of their mother. Female river dragons are excellent parents and will also cooperatively protect the broods of others born into the clan; males are mostly passive and indifferent to the presence of the young. Born in litters of up to thirty, tiny young river dragons - born alive like all eelsnakes - form tight schools that keep physical contact to at least one adult nearly all the time while traveling, and these juveniles can feed freely from carcasses brought down by adults without any position in the social hierarchy until they reach about four feet long, at which time they are driven off by the adults and form or join a gang of other juveniles that hunts smaller prey. River dragons of every age rip meat from large carcasses by death-rolling: grasping a mouthful of meat and then spinning to tear it from the body, a behavior shared by both eels and crocodiles on Earth that is the most efficient way to dismember a carcass when you can neither hold it down with hands, nor chew your food. In addition to hunting, these animals scavenge whenever possible, and can pick up the scent of blood from a mile away over air or even further as it travels downstream in the water. They are likely to stake a claim over any carcass brought down close to to shore, emerging together like a many-headed, snapping hydra that even the fiercest land animals will give a wide berth.

Clans of river dragons communicate with each other via both pheromone cues and vocalizations. Male common river dragons, the widest ranging and largest of all species, are notable for their beard of three long feelers, which originate from their chins. These have chemo-sensory abilities, picking up pheromones that indicate females are receptive to mate, and he taps potential partners with them to test her readiness during courtship that is surprisingly tender for such a toothy predator. Males within a clan also compete for the attention of the biggest females by singing, a complex combination of noises that includes stridulation (rapid movements of the bones of their neck vertebrae together to produce a distinctive rattle) and a low-frequency honk produced by shifting air in their swim bladder, that sounds a lot like the calling of a bullfrog. Females respond in turn with mouse-like squeaks from their own swim bladders and clicking calls produced by quickly snapping their jaws together, knocking their front teeth against each other; for animals with no true vocal cords, river dragons can make a lot of noise. Even newborn babies vibrate their tiny swim bladders to produce ultrasonic cries to call their mothers when frightened, which their parent can pick up from a significant distance underwater, hearing via the bones of their skulls.