Four Books Survived
Maní, July 1562. The most successful act of intellectual destruction in recorded history, and the reason you cannot name what was lost is that it worked.
In July 1562, at Maní in the Yucatán, a Franciscan named Diego de Landa held an auto-da-fé and burned the written record of the Maya.
He was explicit about why. The books contained, as he put it, nothing but superstition and the devil's falsehoods. He burned them anyway knowing the Maya valued them, and he noted with some satisfaction that it caused them enormous grief.
Four codices survive. Four. The Dresden, the Madrid, the Paris, and the disputed Grolier, preserved by the accident of being somewhere his soldiers did not reach.
Out of what was probably thousands.
It is worth stating plainly what that means, because the numbers are so lopsided that the mind slides off them.
Everything the Maya had recorded about their own history, astronomy, mathematics, medicine, ritual and philosophy, a literate tradition running for centuries, with a full writing system capable of expressing any sentence in their language, is gone except for four objects. And most of what we know of Maya astronomy comes from one of them. The Dresden Codex contains Venus tables tracking the synodic period to an accuracy of about two hours over five centuries.