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.

• 21144c02pr0002 Animal Body Part, Dinosaur, Indominus Rex Tail, with Spikes and Pin, Metallic Silver Stripes Print this part is a pair of it
• 21353c02pr0001 Animal Body Part, Dinosaur, Indominus Rex Head with Black Pin, Tan Teeth, Red Eyes and Metallic Silver Scales Print this part is a pair of it
• 68444pr0001 Animal Body Part, Dinosaur, Indominus Rex Arm, Right, with Elbow Spikes with Black Claws this part is a pair of it
• 68445pr0001 Animal Body Part, Dinosaur, Indominus Rex Arm, Left, with Elbow Spikes with Black Claws this part is a pair of it
• 98162pr0008 Animal Body Part, Dinosaur, Indominus Rex Leg, Left, with Pin, Metallic Silver Patches and Black Claws Print this part is a pair of it
• 98163pr0008 Animal Body Part, Dinosaur, Indominus Rex Leg, Right, with Pin, Metallic Silver Patches and Black Claws Print this part is a pair of it