In this Stegosaurus skeleton, the pubis and ischium both point backwards.
在这个剑龙骨架中,耻骨和坐骨都指向后方。
阿尔伯塔大学-恐龙古生物学
And that's because the muscles rearrange themselves because they're not moving in the same kind of way and so in an Ornithischian dinosaur, the pubis reorientates itself so that it's back beside the ischium.
The ischium (pronunciation: /ˈɪskɪəm/) forms the lower and back part of the hip bone (os coxae).
Situated below the ilium and behind the pubis, it is one of these three bones whose fusion creates the coxa. The superior portion of this bone forms approximately one third of the acetabulum.