Bones are on top of the tall rocky cliff that makes a long canyon-like walkway. Leave horse below, as you will need to climb around to the top.
There are 3 rewards for finding Dinosaur bones:
1 Dinosaur Bone locations found: Quartz Chunk (used to craft the Bear Claw Talisman: decreases Health Core drain by 10%)
15 Dinosaur Bone locations found: Skull Statue (No known use)
30 Dinosaur Bone locations found: Jawbone Knife
View the Dinosaur Bones Locations Guide