Bellusaurus sui

In 2003, large number of isolated bone of juvenile individuals of the small sauropod Bellusaurus were recovere from the late Middle Jurassic Shishugou Formation at Konglonggou, in the Junggar Basin of Xinjiang. Preliminary morphological analysis of these new material shows that Bellusaurus is unique among sauropods in displaying an unusual combination of the following charater states：posterior end of the prefrontal not protruding beyond the posterior end of the frontal process of the nasal; pineal foramen on the midline of the frontal-parietal suture present; U-shaped notches on the dorsal aspect of the lateral and medial walls by which the pterygoid expanded both posterodorsally and posteroventrally; a distinct fossa on the medial wall of the quadrate process of the pterygoid; troughlike structure on the dorsal margin of the quadrate process and merging anteriorly with the medial surface; basal articular area for reception of the basipterygoid process on the anteromost part of the medial surface of the quadrate process; large, deep pleuroceol present in the centrum of axis; anterior and middle cervical neural spines anteroposteriorly long, extending over the posterior half of the neural arches; anterior and middle cervical neural spines very low, with their dorsal margins weakly convex; a midline lamina present just on the dorsal surface of the dorsal neural canal; intraprezygapophyseal lamina (tprl) present in the middle and posterior dorsal neural arches; hyposphene-hypantrum system in the middle and posterior dorsal vertebrae weak or absent; "V" or "Y" shaped laminae present on the anterior surfaces of the middle and posterior dorsal neural arches; neural spines of the anterior and middle dorsals strongly compressed anteroposteriorly; forked spinodiapophyseal laminae (spdl) of the middle and posterior dorsals connecting anteriorly and posteriorly with the spinoprezygapophyseal laminae (sprl) and spinopostzygapophyseal laminae (spol), respectively; deep groove present between the parallel prezygodiapophyseal laminae (prdl) and paradiapophyseal laminae (ppdl) of the middle and posterior dorsals; anterior caudals procoelous; lateral surfaces of the middle caudal centrum straight.