Zapotec writing

From the Wikipedia page on Mesoamerican writing systems 
One of the candidates for earliest writing system in Mesoamerica is the writing system of the Zapotec culture. Rising in the late Pre-Classic era after the decline of the Olmec civilization, the Zapotecs of present-day Oaxaca built an empire around Monte Alban. On a few monuments at this archaeological site, archaeologists have found extended text in a glyphic script. Some signs can be recognized as calendric information but the script as such remains undeciphered. Read in columns from top to bottom, its execution is somewhat cruder than that of the later Classic Maya and this has led epigraphers to believe that the script was also less phonetic than the largely syllabic Maya script. These are, however, speculations.
The earliest known monument with Zapotec writing is a "Danzante" stone, officially known as Monument 3, found in San Jose Mogote, Oaxaca. It has a relief of what appears to be a dead and bloodied captive with two glyphic signs between his legs, probably representing his name. First dated to 500–600 BCE, this was earlier considered the earliest writing in Mesoamerica. However doubts have been expressed as to this dating and the monument may have been reused. The Zapotec script went out of use only in the late Classic period.
There is various other coverage eg and .
Category:Undeciphered writing systems