This research lays the groundwork for using fossil snail shells to reconstruct seasonal precipitation distributions and extreme rainfall events in the geological past. In high latitude regions ...

The fossil is Shishania aculeata ... prior to the evolution of the shells that we see in modern snails and clams.” The study is published in the journal Science.

The paper said the work could be extended to a large number of fossil snail shells preserved in the Loess Plateau in north-central China that might reconstruct a relationship of extreme rainstorms ...

Here's the story of how a fossil is made. This is an ammonite. Ammonites were once sea creatures with squid-like tentacles and a curly shell like a snail. They lived at the same time as dinosaurs.