Peteinosaurus was one of the earliest Pterosaurs, dating to the Mid Triassic Period, around(225-200)Though not the earliest Pterosaur known, with Early Triassic relatives, it was one of the very earliest Pterosaurs to become widely successful, clearly establishing reptiles as 'the new masters of the air.
It was a comparatively small Pterosaur of the characteristic long-tailed Rhamphorhynchids, at around 40-60 centimetres in wingspan. Its diet would have consisted largely of insects, such as Dragonflies, due to its tiny but very sharp needle-like teeth.
A peteinosaurus is seen to be chasing dragonflies near the beginning of the episode. Kenneth Branagh describes how the animal's minute and blade-like teeth are well suited to the consumption of insects, and how it was likely an insectivore.
Later on, a male peteinosaurus bathes in a stream to keep cool in the harsh Triassic heat. Due to the dry season's ability to generate high tensions between animals, he "constantly checks for danger". His fate remains unknown.
- It is now known that pterosaurs (including peteinosaurus) had bat like fur on their bodies.