Evolution What the Fossils Say and Why it Matters

FIGURE 12.8. (A) The primitive marginocephalan Yinlong, which shows skull features linking both horned
dinosaurs (ceratopsians) and the bone-headed pachycephalosaurs. (B) The complete articulated skeleton of
Yinlong. For explanation of labels see Xu et al. (2006) (Photos courtesy J. Clark, George Washington University)

(A)

lpe lis lt lf lm lu lh rib ls

cv rpe rt ri rfi rf lp rmdv rh rs cev

5 cm

sk

(B)