While oviraptorids were generally one to eight metres in body length, Yulong was described as "chicken-sized" by its describers.
Most of the Yulong individuals had a total body length of a quarter to half a meter, making them some of the smallest known oviraptorids.

The describing authors established some diagnostic traits.
The front upper corner of the fenestra antorbitalis and the rear upper corner of the bony nostril are positioned at about the same height.
The premaxilla shows a distinctive opening below and in front of the nostril.
The rear upper process of the premaxilla touches the upper rim of the fenestra antorbitalis but not the front process of the lacrimal; both bones are separated by the nasal bone.
The parietal approaches the frontal bone in length.
 At the fourth and fifth neck vertebrae, the rear edge of the vertebral centrum forms a straight line between the postzygapophyses.
The thigh bone is longer than the ilium.

According to the authors, the hindlimb proportions of oviraptorids do not essentially change during growth, indicating a more sedentary lifestyle and thus probably herbivory.
While oviraptorids were generally one to eight metres in body length, Yulong was described as "chicken-sized" by its describers. Most of the Yulong individuals had a total body length of a quarter to half a meter, making them some of the smallest known oviraptorids.
The describing authors established some diagnostic traits. The front upper corner of the fenestra antorbitalis and the rear upper corner of the bony nostril are positioned at about the same height. The premaxilla shows a distinctive opening below and in front of the nostril. The rear upper process of the premaxilla touches the upper rim of the fenestra antorbitalis but not the front process of the lacrimal; both bones are separated by the nasal bone. The parietal approaches the frontal bone in length.  At the fourth and fifth neck vertebrae, the rear edge of the vertebral centrum forms a straight line between the postzygapophyses. The thigh bone is longer than the ilium.
According to the authors, the hindlimb proportions of oviraptorids do not essentially change during growth, indicating a more sedentary lifestyle and thus probably herbivory.
Yulong mini