Here, an image from the Grolier Codex, a Mayan text that researchers now say is authentic.

The authenticity of the Grolier Codex has been disputed for the last four decades. A group of researchers who revisited the rare Maya text now argue that there's no way it could be a forgery.

If the 800-year-old Grolier Codex is indeed authentic, it would be the oldest known paper manuscript from the Americas, and one of just four Maya codices that are known today.

The fragmentary codex is made up of 10 painted pages full of Maya hieroglyphs, depictions of deities and a calendar that tracks the movement of the planet Venus, which was important for keeping religious rituals. [Photos: Maya Mural Depicts Royal Advisors]

The calendar spans 104 years, meaning the codex could have been used by at least three generations of calendar priests or "day-keepers," the authors of the new study wrote. For the Maya, Venus was an omen for unfortunate events, and the different cycles of the planet were linked to particular gods—most of whom are depicted in the Grolier Codex as dangerous, holding weapons like spears, darts and knives used for beheading.

Shady provenance

When it surfaced in the 1970s, the codex was eyed as a possible forgery. Those suspicions arose in part because of the manuscript's shady collecting history; it was not discovered by archaeologists, but looters, who sold it to a Mexican private collector JosuéSáenz in the late 1960s.

Sáenz presented what many scholars thought was an outlandish story about how he had acquired the manuscript. He said he was taken in a light plane to a remote airstrip in an undisclosed location in the Mexican state of Chiapas. There, the looters allegedly showed him the codex —along with other Maya artifacts, including a wooden mask and a child's sandal—and told him that the objects had been found in a cave.

According to the research consortium Trafficking Culture, Sáenz allowed archaeologist Michael Coe to display the text at theGrolier Club in New York (hence the name of the codex) where it gained international attention. It then apparently sat for years in the basement of the Mexican National Museum of Anthropology.

"It became a kind of dogma that this was a fake," study researcher Stephen Houston, an archaeologist at Brown University, said in a statement. "We decided to return and look at it very carefully, to check criticisms one at a time."

Evidence of authenticity

Coe, Houston and two other researchers have just published their 50-page reassessment of Grolier Codex in the journal Maya Archaeology.

Among the supporting evidence they present are radiocarbon dates that show the manuscript dates back to the 13th century. This would suggest the text was created toward the end of the early post-Classic period (A.D. 900–1250), when both Chichen Itza in Yucatan and Tula in Central Mexico were falling into decline, and the authors say that the Grolier Codex contains imagery similar to what's been found at those two archaeological sites.

Skeptics had previously argued that a hoaxer could have created a forgery using genuinely ancient Maya paper. But the researchers also argue that the codex bears features that Mayanists in the 1960s didn't fully understand, and so a forger wouldn't have been able to create such features. The manuscript, for instance, contains images of deities that hadn't yet been discovered, the authors write, and some of the paintings are rendered in a pigment known as "Maya blue," which hadn't been accurately synthesized in a lab until the 1980s.

"A reasoned weighing of evidence leaves only one possible conclusion: four intact Maya codices survive from the pre-Columbian period, and one of them is the Grolier," the authors wrote.

The three other Maya codices —which are much longer and in better condition than the Grolier Codex —are the Dresden Codex, the Madrid Codex and the Paris Codex, each named after the city where the text is housed. It's not that the Maya didn't produce many written records. But many texts were written on organic material like strips of paper made from the inner bark of fig or mulberrytrees, and they likely disintegrated under the wet conditions of Central America. Still, others were deliberately destroyed by European Christians who saw the manuscripts as heretical works.

Some book burnings were even described in colonial accounts that would make any historian's heart sink. For example, one 16th-century Spanish Franciscan friar named Diego de Landa wrote about finding a large number of Maya books that contained "nothing in which there was not superstition and lies of the devil," so, he and his fellow missionaries burned them all, which the Maya, unsurprisingly, "regretted to an amazing degree."

Original article on Live Science.