Experts are studying the first Mayan hieroglyphic script dealing with the life of a high priest, his blood sacrifices and acts of penance, Mexico's National Institute of Anthropology and History (INAH) said.
The text consists of 260 glyphs carved into a series of seashell earrings and manta ray stingers found inside a burial urn.
The urn, which also contained the remains of an important Maya priest, wrapped in bright red cloth, was uncovered during excavations 11 years ago in Comalcalco, in southeastern Tabasco state, the institute said in a statement.
"It is the longest Maya hieroglyphic script ever found to date in Tabasco" and the first relating a high priest, instead of a Maya ruler and his wives, INAH said.
The text covers 14 years in the life of a Maya priest who lived in the eighth century A.D. It includes references to blood sacrifices and acts of penance preceding the spring solstice.
Maya priests used manta ray stingers to pierce their earlobes, tongue, forehead, penis and other parts of the anatomy, in painful, bloodletting sacrifices to induce a hallucinogenic state in which they believed they could talk to their gods, INAH said.
One of the glyphs refers to the equivalent modern date of January 31, 771.
The Maya dynasties flourished between 426 and 820 AD throughout much of Central America and south eastern Mexico. They excelled in architecture, astrology, mathematics and in keeping several, extremely accurate calendars.