A tantalising snippet from Archaeology.org news round up:

Guatemala - San Bartolo, site of the Maya world's earliest murals, rewrites scholarship with the discovery of the oldest-known Maya writing in the rubble of the site's Las Pinturas pyramid. Dating to 250 B.C., the six-inch-long strip of glyphs is 500 years older than the earliest solidly dated Maya text. Only the glyph ajaw, meaning "ruler," has been identified, but the text is clearly rendered, indicating that Maya literacy must date to even earlier.