It is distinguished from other derived Choristodera in that the short mandibular symphysis, less than 20% the length of the lower jaw, and the nearly square tooth alveolus.

• 朝阳辽西龙的下颌缝合部短,小于下颌长度的20%25,牙齿齿槽近似正方形,区别于任何已知的进步的离龙类。