Olmec colossal heads the monuments with ropes. Two heads from San Lorenzo have traces of niches that are characteristic of monumental Olmec thrones and so were definitely reworked from earlier monuments. Seventeen confirmed examples are known. An additional monument, at Takalik Abaj in Guatemala, is a throne that may have been carved from a colossal head. This is the only known example outside of the Olmec heartland on the Gulf Coast of Mexico. Possible fragments of additional colossal heads have been recovered at San Lorenzo and at San Fernando in Tabasco. Crude colossal stone heads are also known in the Southern Maya area
Olmecs earlier Olmec writing system and Mayan writing, the matter remains unsettled. The Long Count calendar used by many subsequent Mesoamerican civilizations, as well as the concept of zero, may have been devised by the Olmecs. Because the six artifacts with the earliest Long Count calendar dates were all discovered outside the immediate Maya homeland, it is likely that this calendar predated the Maya and was possibly the invention of the Olmecs. Indeed, three of these six artifacts were found within the Olmec heartland. But an argument against an Olmec origin is the fact that the Olmec civilization had ended by