Quetzalcoatl

Science used to tell us that dinosaurs and related reptiles had a smooth leathers skin.  The science was settled.

Then science told us that some dinosaurs and similar reptiles had feathers.  Once again the science was settled.

Anthropologists told us the Aztecs told us that they were in contact with Quetzalcoatl, a flying feathered serpent.

 Paleontologist tell us that men and dinosaurs never lived together.  The science was settled.

  Quetzalcoatlus, the feathered serpent flying reptile did exist say Paleontologists.  But how did the Aztecs know this if they did not see them?