Also, Green Ronin put out a series of historically based (semi-historically based) supplements that they call Mythic Vistas. Many of them are out of print, now, but I'm sure you can find them--at least a pdf. One you might be interested in is called
Mythic Vistas: Skull & Bones. Think Pirates of the Carribbean, and you'll be in the right frame of mind for it. Pirates. Jungles. Dark sorcery.
Some of the other Mythic Vistas books may interest you. Look around.
FMQ1: City of Gold is an adventure for the Maztica set you just bought. You know that there's a trilogy of novels set in Maztica, right?
FMA1: Fires of Zatal is another Maztica adventure.
FMA 2: Endless Armies is its sequel.
Avalanche Press published a supplement for d20 3E called
Aztecs: Empire of the Dying Sun.
GURPS has an
Aztecs book. GURPS also has a highly regarded
Dinosaurs book. Plus, GURPS has an Ice Age book and a lost worlds type supplement called
Lands Out of Time.
Lost Prehistorica is a generic d20 supplement.
Primal Codex is another generic d20 supplement for playing in primitive settings.
The old Timemaster RPG has a supplement called
Temples of Blood.
Empire of the Petal Throne is an RPG with a science-fantasy setting based on ancient South America and ancient India.
Ronin Arts published an Aztec-themed adventure called
The Ixiptia.
Heirs to the Lost World is an rpg set during the Spanish exploration of the Americas.
And, check this out:
This is an RPG, with a horror slant, set among the Aztecs.
I'm sure that you can find more stuff by just googleing a bit.