Lucy

The script took nine years to complete.

The Native Americans shown in ancient Manhattan are Plains Indians not native to New York. Also, they are riding horses which are not native to the New World, but introduced by Europeans. However, during her journey, Lucy moves not only through time, but also keeps changing location (when meeting ancient Lucy, she is arguably in Ethiopia). So it is very possible that she encounters those American natives somewhere in the western plains, and at a time when horses had already been introduced to the continent.

Featured in The Tonight Show Starring Jimmy Fallon: Morgan Freeman/Kesha/Tweedy (2014)