Baku, April 14, AZERTAC

Archaeologists in Guatemala have discovered the oldest evidence of the Maya calendar on record: two mural fragments that, when pieced together, reveal a notation known as "7 deer," a new study finds.

The two "7 deer" fragments date to between 300 B.C. and 200 B.C., according to radiocarbon dating done by the research team. This early date indicates that this Maya divination calendar, which was also used by other pre-Columbian cultures in Mesoamerica, such as the Aztecs, has been in continuous use for at least 2,300 years, as it is still followed today by modern Maya, the researchers said. (Notably, this is not the Long Count calendar that some people used to suggest the world was going to end in 2012.)

"It's the one calendar that survives all the conquests and the civil war in Guatemala," the latter of which was waged from 1960 to 1996, study first author David Stuart, the Schele professor of Mesoamerican art and writing at the University of Texas at Austin, told Live Science. "The Maya of today in many communities have kept it as a way of connecting to their ideas of fate and how people relate to the world around them. It's not a revival. It's actually a preservation of the calendar."

The researchers found the mural fragments at the archaeological site of San Bartolo, northeast of the ancient Maya city of Tikal. Stuart was part of the team that discovered San Bartolo in 2001. "It's in the remote jungles of northern Guatemala" and famous for its Maya murals dating to the Late Preclassic period (400 B.C. to A.D. 200), he said.

The murals at San Bartolo are in a massive complex known as Las Pinturas, which the Maya built over hundreds of years. Every so often, the Maya would build over an old complex, constructing larger and more impressive structures. As a result, Las Pinturas is layered like an onion. If archaeologists tunnel into its inner layers, they can find earlier structures and murals, Stuart said.

The researchers collected ancient organic material, such as charcoal, within the layer where the mural fragments were discovered. By radiocarbon-dating these fragments, they could estimate when the murals were created.

However, these murals weren't in one piece. In total, the team discovered about 7,000 fragments from various murals. Of this colossal collection, the team analyzed 11 wall fragments, discovered between 2002 and 2012, with radiocarbon dating. These included the two pieces that formed the "7 deer" notation, which includes a glyph, or image of a deer under the Maya symbol for the number seven (a horizontal line with two dots over it).