Xunmenglong

Xunmenglong is the smallest known member of the compsognathid group, about the size of a sub-adult Scipionyx, another small dinosaur.1

Its lower legs were unusually long compared to the rest of its body, which may have made it a fast runner.2

The fossil was originally part of a chimera, meaning it was mixed with bones from two other animals before scientists sorted it out.1

Xunmenglong lived about 130.7 million years ago, during the Hauterivian age of the Early Cretaceous.1

It is the oldest known compsognathid from Asia, found in the Huajiying Formation which may preserve the oldest Jehol Biota fauna.2

One unique feature is that its fourth toe bone (pedal phalanx IV-4) is longer than the third, which helps tell it apart from other compsognathids.2