"Pelvis of Echidna. S., Sacrum; Ep., epipubic bones; Ac., acetabulum; o.f., obturator foramen between ischium and pubis (p.)." -Thomson, 1916

Echidna Pelvis

"Pelvis of Echidna. S., Sacrum; Ep., epipubic bones; Ac., acetabulum; o.f., obturator foramen between…