Fig. 4 Astragali (bone of the ankle) of the raoellid Indohyus (RR
224), the pakicetid Pakicetus (H-GSP 98148), a modern pig (3/84),
and a modern deer (2/93). This shape of the astragalus, with a
proximal trochlea (hinge joint) as well as distal trochlea, only occurs
in even-toed ungulates (artiodactyls)