Looking at a promate skull, in general, how could you tell if it were stereoscopic vision?

Question

Looking at a promate skull, in general, how could you tell if it were stereoscopic vision?

Answer 1

All animals that have two forward facing eyes have stereoscopic vision, including primates.  The benefit of stereoscopic vision is that it gives a more precise depth perception and is a common feature of predators which rely on vision, although it is also a common feature of primates which have varried diets from gumivores, and insecivores all the way through to herbivores and omnivores (this is not a complete list of dietary types).  Presumably stereoscopic vision became a priority in primates because of moving in arboreal environments and/or to assist in using our opposable thumbs to manipulate things in our environment to process or catch foods (insects, nuts... etc).  Prey species meanwhile benefit from panoramic vision because it allows them to survey more of the lanscape at once so that they can be alerted to jump into action if they need to escape.  Stereoscopic vision works by creating a binocular disparity/parallax which allows your brain to determine depth intuitively.  You can test your own stereoscopic vision by holding your finger up about 30 cm (1 foot) in front of your face and watching it jump back and forth as you switch between which eye is open to view it with.  The morphological feature that will identify this when looking at the osteological remains of a primate cranium would be that the eye sockets would be forward facing.  Each individuals brain will adapt to the distance between the eyes to determine distance with relative precision, but the further apart the eyes (cameras/telescopes) the more precise that the distance can be measured.  If you were to look at the stars with your human eyes you would never be able to tell from sight how far a star is, but by targeting that same star with two (or more) telescopes far apart from each other on our planet it becomes possible to use this binocular disparity/parallax to determine distances even as great as that of the stars!

Answer 2

In a "primate" skull?

The orbits (eye sockets) are close together and face forward.

All primates have stereoscopic vision to some degree.