Find the type of index fossil that existed for the shortest period of time

Index fossil, any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment.

polisit can also mean a body of citizens. in modern historiography, polis is normally used to indicate the ancient greek city-states, like classical athens and its contemporaries, and thus is often translated as "city-state". the body of citizens came to be the most important meaning of the term polis in ancient greece.

battle of the bulge, but are there any multiple choice options?