Xiaotingia

Xiaotingia had long, strong arms and hands, which scientists used to think were special bird features, but they are actually found in a bigger group called Paraves.2

When Xiaotingia was added to the family tree, it made Archaeopteryx move from being a bird to being a raptor, which surprised many scientists.2

Xiaotingia had a large hole in its lower jaw, called a surangular foramen, that was more than 6% of the total jaw length.1

Its fourth finger bone (metacarpal IV) was thicker than the second and third, which is unusual.1

Xiaotingia shared some features with troodontids, like closely packed teeth in the front of the jaw and long, slender tail bones.1

The only known fossil was bought from a fossil dealer, so scientists are not 100% sure exactly which rock layer it came from.1