Searching along the floor of an ancient sea

One recent Saturday morning, I took my six-year-old, Clara, to a fossil dig sponsored by the Paleontological Research Institution (PRI) of Ithaca, N.Y. About 100 of us gathered at one of the best and most accessible fossil-hunting sites in the area. It's a small shale cliff not far from the east shore of Cayuga Lake.

"We are now standing on what used to be the soft mud bottom of a warm, shallow sea during the Devonian period," explained Rob Ross, PRI's education director. "That was 380 million years ago," he added.

The "family fossil dig" was attended by adults and kids of all ages armed with rock hammers (ordinary hammers are not safe to use on rocks), garden trowels, safety goggles, buckets, and plastic bags.

Clara and I sifted through the loose shale piles at the base of the cliff. Others picked at the shale that was still in place. We were looking for fossil trilobites (TRY-loh-bytes) and brachiopods (BRACK-ee-oh-pods), little critters that lived in the shallow sea.

"You've got to have a keen eye," said a seven-year-old boy who was working the pile with me.

Dr. Ross circulated through the crowd, examining and identifying the fossils found. "It's a bit like a treasure hunt," he said. "You might find something great, or your neighbor might." That made us search harder.

After about an hour of searching, Clara and I left with about 20 fossil specimens in our red bucket -including one very cool rolled-up trilobite that looked just like an overgrown modern-day pill bug.

To find good places to hunt for fossils in your area, contact a local natural-history museum, the geology department of a nearby university, or your state's geologic survey. Many areas also have local gem and mineral clubs whose members might also know where to look for fossils.