While trilobites existed throughout the Paleozoic era (541 to 252 million years ago), they were especially abundant in the Devonian period (419 to 359 million years ago). This makes them a quintessential Devonian fossil.

Here are some other common Devonian fossils:

* Brachiopods: These marine animals with two hinged shells were very diverse during the Devonian.

* Crinoids: These are "sea lilies" with feathery arms that were attached to the seafloor.

* Coral: Many types of coral reefs flourished in the Devonian.

* Fish: The Devonian is often called the "Age of Fishes," as many types of fish evolved during this period, including early sharks and bony fish.

* Ammonites: These coiled cephalopods became more diverse during the Devonian.

The specific fossils you're likely to find will depend on the location and the type of rock. However, trilobites are a good starting point for anyone looking for Devonian fossils!