Variants of a mold are catalogued separately, so each one has its own sets and minifigs. Check these too if something you expect is missing here.

• 98172 Animal Body Part, Dinosaur, Triceratops / Ankylosaurus Leg, Left, Rear / Hind, with Pin [Plain] this part is a print of it
• 98173pr0003 Animal Body Part, Dinosaur, Ankylosaurus Leg, Right, Rear / Hind, with Pin, Light Bluish Gray Nails and Medium Nougat Patches Print this part is a pair of it