Complex sentence: The "Dresden Codex" is a thirteenth or fourteenth-century book of the Yucatecan Maya of Chichén Itzá that is the oldest surviving book from the Americas.
Split into simpler sentences: The "Dresden Codex" is a thirteenth or fourteenth-century book of the Yucatecan Maya of Chichén Itzá. It is the oldest surviving book from the Americas.