In 1521, a small group of conquistadores led by Hernán Cortés arrive in Mexico seeking fame and fortune when they discover and are captured by an Aztec tribe that worships and regularly performs ritual sacrifices to a mating pair of Tyrannosaurus rex which they call Thunder Lizards.
When Cortes second-in-command, Rios saves the tribes princess Ayacoatl from one of the dinosaurs and he gains the gratitude of her father, the village chief. The Spanish explorers and Aztecs then decide to set out and slay the beasts once and for all.
- Action Bomb: A gunpowder bomb is used to defeat the female T-Rex.
- Alternate History: This movie has Spanish explores discover a tribe of Aztecs that worship a pair of Tyrannosaurus Rex which are somehow alive 65 million years after when they are supposed to be extinct.
- Arrows on Fire: One is shot from a crossbow by Rios to ignite a gunpowder bomb in order to kill the female tyrannosaur.
- Artistic License Biology: The two tyrannosaurs are somehow able to sustain themselves on what appears to be a diet of human hearts and the only animals that they could prey on in the region would be smaller mammals, birds, lizards and crocodilians which would likely not provide enough food for a pair of 7-9 ton dinosaurs.
- Artistic License Paleontology: The Tyrannosaurs are portrayed as traditionally scaly, T-rex is now considered to have most likely been at least partially feathered, although the idea of feathered theropods wasnt so prominent when the film was released and it clearly had a very limited special-effects budget. Its possible the Thunder Lizards in the film could have lost their feathers during 65 million years of continued evolution.
- Chekhov's Gun: The horn made from the tooth of a tyrannosaurus that is used to summon the dinosaurs to sacrifices is later used in order to lure the male tyrannosaur to the spaniards trap.
- Everything's Better with Dinosaurs: The movie invokes this trope by introducing two dinosaurs into a Mesoamerican setting.
- God Guise: The Aztecs worship the two dinosaurs as dragons/gods.
- Historical Domain Character: Hernán Cortés is one of the main characters.
- Inertial Impalement: The male tyrannosaur is killed when it is lured by Rios into a spike pit.
- King of the Dinosaurs: The Spaniards have to battle a pair of Tyrannosaurus Rex, which the Aztec tribe both fears and worships as gods.
- Last of Their Kind: It is mentioned that there used to be many thunder lizards but now there are only two, making them the last mating pair of their kind. The female Tyrannosaur specifically becomes the last when her mate is killed.
- Living Dinosaurs: Two Tyrannosaurus Rex are alive during the time of the Aztec Empire.
- Medieval Prehistory: A population of Tyrannosaurus rex have managed to survive into the 16th century.
- T. Rexpy: The Thunder Lizards are odviously descended from Tyrannosaurus rex, however they are never referred to as T-Rexes because of the fact that the name wasnt coined until several centuries after the first Spaniards arrived in the Americas.