We have buried capsules with things from the present in case we cease to exist and another inhabit our land one day so they can find it and know about our civilization.
If the inhabitants of the earth of 30,000 years ago were the same as modern man where is their information they left for us to find?
In Iraq in the Shanidar Cave.
Neanderthals, who lived > 10,000 years ago, held burial rituals for thier dead.