Megalancosaurus

Anatomy

Megalancosaurus was fairly small, its adult length was only about 25 centimeters (10 inches). It was built like a chameleon and probably lived a similar arboreal lifestyle, feeding on insects and other small animals. Even its feet were chameleon like, with two toes being opposed to the remaining three. The tail is long, prehensile, and bears a strange claw-like organ made of fused vertebrae at its end. Its shoulders formed a withers that would have served as an attachment site for especially strong muscles.

Some specimens have an opposable digit on the feet. Because not all members of the species appear to bear this digit, it has been speculated that it is an instance of sexual dimorphism, only being possessed by whichever sex needed a stronger grip on the branch during copulation.

The head of Megalancosaurus is superficially very birdlike. The skull was roughly 30 mm long and 12 mm tall. The eyes were large and the snout was narrow. Towards the tip of the snout were two small premaxillary teeth, which were separated by a diastema from at least 22 small maxillary teeth. The orbits were directed anteriorly, suggesting that Megalancosaurus had good binocular vision.

It has been proposed that Megalancosaurus was capable of gliding, though while not fully ruled out it has largely been dismissed.

The two species of Megalancosaurus were able to coexist by living in different microhabitats such that they did not occupy the same niche.