People living along the coast of Peru were eating popcorn before they had pots to put it in, and 1,000 years earlier than thought.
A research group led by Tom Dillehay from Vanderbilt University and Duccio Bonavia from Peru's Academia Nacional de la Historia has found some of the oldest known corncobs, husks, stalks and tassels at Paredones and Huaca Prieta.
They date from 6,700 to 3,000 years ago, so appeared quite a while before movie theaters too.
The cobs are the earliest ever discovered in South America, and show that the locals ate corn several ways, including popcorn and flour corn, although it wasn't an important part of their diet.
"Corn was first domesticated in Mexico nearly 9,000 years ago from a wild grass called teosinte," says Dolores Piperno, curator of New World archaeology at the Smithsonian's National Museum of Natural History.
"Our results show that only a few thousand years later corn arrived in South America where its evolution into different varieties that are now common in the Andean region began. This evidence further indicates that in many areas corn arrived before pots did and that early experimentation with corn as a food was not dependent on the presence of pottery."
The team believes that these new and unique races of corn may have developed quickly in South America, where there was no chance that they would continue to be pollinated by wild teosinte.
"Because there is so little data available from other places for this time period, the wealth of morphological information about the cobs and other corn remains at this early date is very important for understanding how corn became the crop we know today," says Piperno.