Earliest evidence of Maya calendar found inside Guatemalan pyramid

An undated artist's reconstruction of the ceremonial structures dating to about 200 BC to 300 BC at the San Bartolo Preclassic ancient Maya site in Guatemala where evidence was found for the earliest use of the Maya calendar. Heather Hurst/Handout via REUTERS

WASHINGTON (Reuters) - A glyph representing a day called "7 Deer" on mural fragments dating from the third century BC found inside the ruins of a pyramid in Guatemala marks the earliest-known use of the Maya calendar, one of this ancient culture's renowned achievements.

The fragments were found at the San Bartolo archeological site in the jungles of northern Guatemala, which gained fame with the 2001 discovery of a buried chamber with elaborate and colorful murals dating to about 100 BC depicting Maya ceremonial and mythological scenes, researchers said on Wednesday.