To me, this looks more like a form of accounting.
Each mark represents something owed or something paid: In effect, it's a "chit".
(Was unsure of the exact meaning of chit, so I googled it:
Chit: A short official note, memorandum, or voucher, typically recording a sum owed.)
Capuchin monkeys can be taught the concept of money. They understand debt:
http://scholar.google.com/scho...
I haven't seen any studies where they spontaneously create art, though, which leads me to believe that accounting could appear earlier.
"Deliberate Markings", yes, which is significant and amazing, but undoubtedly some fool is going to claim that it is "unmistakeable proof that the ancients worshiped the ocean waves" or that it was carved by a shaman as a form of divination.