"Explain that an index fossil is like a bookmark of sorts. It is used by scientists to help date specific rock layers. Only fossils that are abundant, existed as a species for a relatively short time, and are dispersed around the world are designated as index fossils."
"Revisiting our newspaper analogy, index fossils would be the equivalent of major news stories recorded by all countries (e.g., the fall of the former Soviet Union), ..."
""A good index fossil is like a gheri curl--it was widespread, and lots of examples exist in the record of history, but it was only around for a very short time.""
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.