Pneumatoraptor differs from other
theropods in having a narrow shoulder blade that is nearly circular in cross section, as well as having a large opening in the bone to house a hollow air sac cavity. The bone is small, indicating that the animal was about three times smaller than
Velociraptor. The shoulder girdle is L-shaped, showing it to be a member of the group
Paraves, which also includes the
dromaeosaurids,
troodontids, and
birds. While the
Pneumatoraptor remains are too incomplete to tell which, if any, of these specific groups it belongs to, many of the features of the bones are similar to dromaeosaurids. Other paravian remains from the same formation may belong to
Pneumatoraptor. These include isolated teeth, claws, tail vertebrae, and a partial lower leg bone (tibia). == References ==