Archaeologists working at the Xultun ruins of the Mayan civilisation¹ have reported striking finds, including the oldest-known Mayan astronomical² tables.

工作在玛雅文明Xultun废墟中的考古学家取得惊人发现，他们发现一处最古老的玛雅天文表。

preservation³ of the artwork surprised archaeologists, given the dwelling⁴'s shallow depth" src="http://www.enread.com/upimg/allimg/120511/1_120511072459_1.jpg" width="624" height="305" />
The preservation of the artwork surprised archaeologists, given the dwelling's shallow depth
The site, in Guatemala, includes the first known instance of Mayan art painted on the walls of a dwelling.

A report in Science says it dates from the early 9th Century, pre-dating other Mayan calendars by centuries.

Such calendars rose to prominence⁵ recently amid claims they predicted the end of the world in 2012.

The Mayan civilisation occupied Central America from about 2000BC until its decline and assimilation following the colonisation by the Spanish from the 15th Century onwards. It still holds fascination⁶, with many early Mayan sites still hidden or uncatalogued.

The ruins at Xultun were first discovered in 1912 and mapping efforts in the 1920s and 1970s laid out much of the site's structure.

Archaeologists have catalogued the site's features, including a 35m-tall pyramid, but thousands of structures on the 30 sq km site remain unexplored.

In 2005, William Saturno, then at the University of New Hampshire, discovered the oldest-known Mayan murals at a site just a few kilometres away called San Bartolo.

In 2010, one of Dr Saturno's students was following the tracks of more recent looters at Xultun when he discovered the vegetation-covered structure that has now been excavated⁷.

When Mayans renovated⁸ an old structure, they typically collapsed⁹ its roof and built on top of the rubble¹⁰. But for some reason, the new Xultun find had been filled in through its doorway¹¹, with the roof left intact.

Dr Saturno, who is now based at Boston University, explained that despite it being under just a metre of soil today, that served to preserve the site after more than a millennium¹² of rainy seasons, insect traffic and encroaching plant and tree roots.

"We found that three of the room's four walls were well preserved and that the ceilings were also in good shape in terms of the paintings on them, so we got an awful lot more than we bargained for," he said.