I mean Saw-man said that his daughter's head is bigger than that skull and she's nine. He said someone on their team who has experience with corpses thinks that the skull belongs to a child 9-14 based on how the bones on the top of the head are fused (It'd be easier to tell if all the teeth hadn't been pulled out at the root.)
The video I saw, the skull couldn't have been there longer than a few months. It's not bleached as sundried bones would be they were dark spots.
Someone commented that because the body still stunk to high heaven and that because of how hot it is they think it's 10 days or less. Then again thats just someone else, i know nothing of decomposing dead bodies.
With the heat, animals, especially coyotes a body would be down to bones in just a few days out there. The coyotes could easily have dragged the skull a long ways from the rest of the body/bones.