Write Team: On the hunt for fossils

So we got way into fossils, our family did. Little rocky treasures. Little bits of evidence of life millions and millions and hundreds of millions of years before Man. And Woman. And Kids ... cars, TV and space flight.

We picked up brachiopods from a local road cut along the way to Oglesby. And crinoids, too, at another road cut locally.

All of this fossil hunting reminded me of a fantastic sixth-grade science class and science teacher I had. My first male teacher, he had superb models of World War II airplanes in his classroom and a huge rock collection. To this day, when I hike, I try to figure out what the rocks are and try to remember those sixth-grade rocks.

I identify the trees and plants in the woods when I hike. Long ago, at about age 13, I used to study a “Forest Trees of Illinois” identification book. I memorized the Latin names of trees and put together a large tree leaf collection in a loose-leaf binder.

But fossils are another order of business. Brachiopod fossils look like clamshells. Brachiopods lived in the great Midwest sea during the Ordovician era about 500 million years ago. The Illinois Valley didn’t exist. It was just all water. Over the years, minerals washed in and filled the cell spaces of the brachiopod shell and they became fossils.

Crinoids are wonderful, flower-like animals that existed long ago. Most crinoid fossils look like little tube beads in rock. The flower portion is hard to preserve and hard to find. We also ran into fossilized bryozoan patches — kind of interesting bits of rocky squiggle.

Out in a tiny crossroads town in Iowa, on a diversion from a trip to Dubuque, we found cephalopods. A road cut there opened up some very ancient history. These lived in low seas and looked like small squid.

Some of these fossils we dropped off at grade schools. It’s nice to have stuff like this for kids to see in the science classroom. Real stuff.

We joined ESCONI, the Earth Sciences Club of Northern Illinois. My family ran around in the IDNR’s fossil park outside of Wilmington looking for Mazon Creek concretions. Concretions are rounded rocks formed by mineral deposits around a core, and the core is sometimes a fossil. We didn’t find many, but in one we found a fossil sea slug or sea worm.

It’s worth pointing out the local Mazon Creek region is known across the world for its unique fossils. Some 309 million years ago, the area was a huge river delta. River sediments covered soft-bodies animals, like insects, before they could decay. Fossils of soft-bodied ancient creatures are rare, so Mazon Creek fossils have helped science.

I’m hoping eventually to find a trilobite. These bug-like fossils were common for a great many eons but they are hard to find here. Informed trilobites could be found in Lemont along the Illinois and Michigan Canal, our family spent a couple of hours looking around but found nothing at all. Trilobites just look cool.

But the coolest fossil is my first fossil. I found it when I was 9. We were walking up the Wenona “Mountain,” the coal mine dump pile. There I found a split-open concretion containing a common Pennsylvanian era fern, the Pecopteris. It just looks cool and it was a lot of fun carrying around in my pocket and taking to school when I was a kid.

  • Todd Volker lives in Ottawa with his wife and son, and they enjoy reading, kayaking, hiking, tennis and camping. He’s a lifelong learner with books in his hands.