Arachnosaurus

While giant spiders are unknown here, arachnophobes are still not safe on Ryl Madol. High up in the canopy lurks a creature appropriately christened Arachnosaurus nychuros. Its prehensile tail makes up over half the body length and is used to lower the animal head-down into the air like a lantern.  The arms and legs are strong and built for climbing, like a chameleon's. The hindlegs are relatively short and tucked close to the body, but the toes are disturbingly long, splayed and tipped with curved claws. Cryptically camouflaged among the vines, Arachnosaurus hangs in wait for hours with its feet stretched out waiting for prey. This may include insects even smaller flying reptiles that happen to fly through the jungle, though the predator also seems to be content with arthropods and “lizards” that happen to waddle a few tree-branches below. Once in reach, Arachnosaurus envelops its prey in a deadly hug it cannot escape from and uses its pointy mouth to feed on it while it is still alive. After the first few bites the prey-animals seem like they are paralyzed, suggesting the use of some type of venom, but autopsies have so far been unable to find venom glands in Arachnosaurus, making this rather mysterious.

Arachnosaurus are surprisingly gregarious, often hanging from the trees in medium-sized groups like bats do, though they do not cooperate when it comes to hunting or fending off predators. They make no audible sounds and instead seem to communicate by changing the color of their headcrest.  Mating usually entails the male presenting the female with a gift in the form of food. After mating, the female builds a nest in a hollowed-out tree-hole and lays its eggs there. The mother guards the nest and even leaves some food behind shortly before the eggs hatch, but once the young emerge they are left to themselves. 

Unlike the anamniotes of the forest floor, Arachnosaurus is a true reptile that lays hard-shelled eggs, though its exact affinity remains uncertain. It appears to descend from some group of basal diapsids, perhaps Araeoscelidia similar to ancient Araeoscelis and Petrolacosaurus.