Click Here to Read: Oldest known example of abstract symbolic representation discovered in Indonesia By Philip Guelpa on the World Socialist Web Site on January 9, 2015.
The geometric pattern on Pseudodon shell, from Left to right, top to bottom: overview (scale bar – 1 cm); schematic representation; detail of main engraving area (scale bar – 1 cm); detail of the engraving (scale bar – 1 mm). [Image credit: Josephine C. A. Joordens et al.]