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.

• 68445pr0001 Animal Body Part, Dinosaur, Indominus Rex Arm, Left, with Elbow Spikes with Black Claws Print of this part
• 112352pr0001 Animal Body Part, Dinosaur, Spinosaurus Body with Dark Tan Belly, Bright Light Orange Markings Print Pair of this part
• 38943pr9999 Animal Body Part, Dinosaur, Indominus Rex Body with Dark Blue Print Pair of this part
• 68444 Animal Body Part, Dinosaur, Indominus Rex Arm, Right, with Elbow Spikes [Plain] this part is a pair of it