Sleeping Dragon

Mei long represents one of paleontology's most extraordinary windows into dinosaur behavior. This diminutive troodontid, measuring just over half a meter in length, was discovered in the volcanic deposits of China's Yixian Formation, preserved in an unmistakably bird-like sleeping position. The holotype specimen shows the animal curled up with its hind limbs folded beneath its body, its long tail wrapped around its torso, and most remarkably, its snout tucked beneath one of its forelimbs—precisely mirroring the sleeping posture of modern birds.

As a troodontid, Mei possessed the hallmark features of its family: large, forward-facing eyes suggesting excellent vision (possibly including nocturnal capabilities), a relatively large brain compared to body size, and the characteristic sickle-shaped claw on its second toe. Its body was almost certainly covered in feathers, evidenced by both phylogenetic inference and the preservation conditions of the Yixian Formation, which has yielded numerous feathered dinosaur specimens.

The volcanic ash that entombed Mei preserved a moment frozen in time, likely representing death during sleep, possibly from toxic gases released during volcanic activity. This exceptional preservation has made Mei long an icon of dinosaur-bird evolutionary connections, demonstrating that behavioral traits we associate with birds evolved long before the origin of true flight. The specimen's pose suggests thermoregulatory behavior, with the tucked position helping to conserve body heat—evidence that at least some small theropods were warm-blooded.