Pteroerpetia is a grandorder encompassing fifty species of endangered species of flying like diaspids descended from Longisquama, first appearing during the late Triassic.
They are diaspids, evolving during the early Jurassic from a population of Longisquama. They have several several adaptations for flying; they have elongated rib like structures supporting a membrane used for flying, these ribs are isolated from the main ones and are not calcified. They also have an enlarged sternum (which serves as a rudimentary keel). They also have robust, streamline bodies filled with tufts of barbs which serve as insulators. They are homeothermic; to supply the animal with energy for flying. They are also neotenous; an adaptation which allowed them to breed premature. Most members have a hollow claw at the end of their tails, which are actually fused tail vertebrae.
They are divided into three miroders, based off molecular studies. Austridracomorpha (southern dragon morphs), Larentiaedracomorpha (Laurentia dragon morphs), Simulgenata (born together). The former is found in all of Gondwana and a small portion of Eastern China. The latter is the rarest, it is found in central Americas and Europe. The middle is the most widespread group, found throughout Laurentia. Molecular studies all support this grouping, and the former and the latter are more related with each other. There is one obscure group called Caudapoda, but its believed to be a member of Austridracomorpha based on morphological studies, however it is quite strange that molecular studies show that it is not related to any miroder but it might well be a basal group. But with a second try it resulted that it was more related to Austridracomorpha.
After the K–Pg extinction a group split off from the early Pteroerpetia and became fully terrestrial, they were isolated in Australia and eventually spread throughout New Guinea and New Zealand and more recently Asia. During the late Eocene they evolved to become aquatic. During the Oligocene though they became more terrestrial, evolving thick scales for protection against the extremely large mammalian predators.
They posses a flap, a relic from their aquatic stage; they also have a long whip-like tail used to whip at targets. They are very similar in biology to monitors and crocodilians as they have a long streamlined body with short, powerful legs that can support sprints; like their distant relatives they are homeothermic allowing them to inhabit more habitats that would be considered uninhabitable by most reptiles.
Like some of their distant relatives, they developed an extra pair of limbs that are used as support for climbing and running. Their skin is patched with hard scaly barbs and soft, but strong scaly skin that is very similar to a bird's skin.
Australian basilisks are the most primitive basilisks and are the mother species for the other basilisks of the world. They are the smallest species, reaching about two meters long and weighing somewhere along the lines of 45 kg (100 lbs). They are much less colorful than their relatives and are a color similar to sand. In fact they primarily hunt by blending into their habitat and waiting for weaker reptilian prey or bulky mammalian prey to misstep. They are largely nocturnal as with most Basilisks and if not able to come out at night, will seek secluded and/or dark areas to rest and hunt in.
The Australian Basilisks migrated upward by swimming across form island to island eventually reaching New Guinea and the Philippine islands. Eventually after thousands of years they reached to tip of China and spread outwards across Eurasia. They evolved larger and more colorful than their ancestors the Australian Basilisks and became more diverse. The Asian Basilisks survived and evolved into new species over the millions of years in Asia becoming very distant. The surviving group in China and with a few subspecies in parts of Korea are about two meters in length and have skin that is primarily light brown with some spots on it's face, back and tails that appear to be golden. This led human beings to hunt them, which ended up driving most of the species into seclusion.
Basilisks in Europe evolved rather differently from it's other relatives. Instead of evolving into a crocodile-like form, they evolved into a smaller more raptor-akin animal. What is unique about this group of Basilisks is that like komodo dragons they have a strong toxic saliva that they use to attack it's prey which largely consists of small amphibians, reptiles, birds and mammals. A species of weasel has evolved convergent to the mongoose and this species is called the Knights weasel is immune to it's venom and is largely responsible for controlling the European Basilisks population by consuming it's eggs. Though they aren't as intelligent as their very distant relatives, they are capable of being domesticated or at least tames, this is notable by people raising them as dogs to protect or patrol dungeons.
Called European dragons, these dragons are one of the most successful and the most intelligent. They originally evolved from an aquatic ancestor that diverged from the Asian dragons. These dragons would eventually take up multiple predatory niches while mammals were still taking up ecological niches.