Figure 1

Proximal right femur (a–c) and tibia (d–f) of Gobihadros mongoliensis. Proximal right femur in cranial (a), caudal (b), and dorsal (c) view. Proximal right tibia in medial (d), lateral (e), and dorsal (f) view. Surface of the proximal femur without transcortical channels (g). Left distal femur of Protoceratops andrewsi (ZPAL MgD-II/11) showing open transcortical channels marked by arrows (h).