The system included choppers, scrapers, and pounders.However, more recent classifications of Oldowan assemblages have been made that focus primarily on manufacture due to the problematic nature of assuming use from stone artefacts.
The most important, but mysterious, type of petroglyph is the cupule - a non-functional cup-shaped hole created by percussion in the horizontal or vertical surface of a rock.
By far the oldest art, cupules have been discovered on every continent except Antarctica, and continued to be created throughout all three eras of the Stone Age.
Cupules have also been referred to as "pits", "hollows", "cups", "cup marks" - even "pot-holes".
Until recent years, scientists who believe in creation haven't had the necessary resources to explore radiometric dating in detail.
A 10 gram sample of U-238Now that has changed, and some important discoveries are being made.