Though stretching the definition of “books” rather far, the Rongorongo deserve a place on this list. These pieces of wood — some of which were shaped into staffs or statuettes — contain a system of glyphs which have not been able to be deciphered since their discovery in the 19th century.
The arrival of Chilean and Peruvian forces on the island had a devastating effect on the population: slave raiders struck a number of times, eventually abducting or killing about 1,500 people, roughly half the native population. Smallpox and tuberculosis epidemics, some of which were purposely introduced by traders. Others were forcibly emigrated to Tahiti as an enslaved work force. Within a decade, 97% of the population was lost, and there was no one left to translate the glyphs.