An anachronism is something in a story that does not fit the story’s time period. Etymologically, it means against time. literarydevices.net gives three Shakespearean anachronisms: Julius Caesar referencing a clock (clocks were not invented until later in history), Hamlet claiming an alma mater that was not yet established, and Macbeth using the word “dollar” before it became a monetary unit.
Vulture.com listicled anachronisms in the greatest story ever told, aka TV show Mad Men. Most, if not all, of these anachronisms are mistakes. All of these anachronisms are of the “This wasn’t around until later in the future” variety. This is known as a prochronism (pro = before, chronism = time). These anachronisms are before their time, therefore they are prochronisms.
Anachronisms after their time, such as a bow and arrow being used in a modern battlefield, are postchronisms.
So, postchronisms are for the Amish and prochronisms are for Marine Expeditionary Units traveling back to Ancient Rome. Both are anachronisms.
P.S.: check out Northeastern University Ben Schmidt’s website, where he seeks linguistic anachronisms in popular TV shows.
An anacoluthon is a “syntactical inconsistency or incoherence within a sentence; especially : a shift in an unfinished sentence from one syntactic construction to another (as in “you really ought—well, do it your own way”)”.
An anacoluthon is the Greek equivalent to the Latin’s non sequitur (the plurals: anacolutha and non sequuntur).
I’d like to give an example before I…oh, I’ll just write an example now.