Ancient Mayan panels dating as far back as the seventh century have been discovered in northern Guatemala, shedding new light on the mysterious civilisation.

In total, three ancient Mayan pieces were excavated at the La Corona and El Achiotal archaeological sites in May. The largest of the pieces measures a metre high and features well-preserved ancient Mayan script and stone carvings.

"Excavations have discovered two hieroglyphic panels, two stone panels about 40 cm in length and about 30 cm in height that are carved with hieroglyphs, and on one of them there's the image of a king dancing," said co-director of the La Corona Archaeological Project Marcelo Canuto.

"These panels are incredibly well preserved and for being about 1,300 to 1,400 years old, we are extremely surprised and excited about the fact that they preserve such wonderful amount of detail."

The priceless artefacts have been moved to Guatemala City for further research. Among the crucial information reportedly carried on the panels are revelations about Mayan transfers of power.

"They're extremely important for us because they give us very detailed information about how a Maya ruler becomes king. It gives us a step-by-step process by which a king over a period of two years is not a royal member of a dynasty and then becomes king of the site," Canuto explained.

"This is fascinating kind of information that is extremely detailed and often not explicated with as much detail in other texts. So, at La Corona we're getting some great, very fine grain information that we don't normally see in text."

Peaking in the eighth century with a population of some 15m people, the advanced ancient empire mapped out a precise calendar and astronomical movements, among other advances.

More about Guatemala