Tomorrow, I will give a presentation at my local library about rocks, fossils, and rock collections. Since I know several people can’t make it to the program, I thought I would share some photos of fossils in my collection to help others identify them. My husband and I started our own collection eight years ago when I took a geology class in college. Hiking around while looking for interesting rocks and fossils became one of our favorite things to do as a free date. Now, our almost 4-year-old has also his own collection of rocks and fossils. Here are some fun ones to look for:
Crinoid or sea lily stems. This aquatic animal looks a bit like an anemone on a stalk. The stems (pictured above) are easy to find. The tops are much more rare. I found the one on the right while hiking with my husband and his parents in Illinois.
Brachiopods, shells with two halves, are even more common than crinoid stems. I have found them in several places over the years. The specimens in this photo I found with my family in Madison, Ind. We found several more specimens along the Ohio River and a road cut along the highway.
Horn coral has a cone-like shape. These samples came from the same road cut near Madison, Ind. This type of coral is the easiest to find.
Branching coral is the type of coral which usually comes to mind when people think about coral. I didn’t have any specimens of coral until our trip to Southeast Indiana last year.
Colonial coral forms with what looks like a repeating pattern. The piece in the right corner is one of my favorite fossils. It looks like the pattern on Petoskey stones, which are common in Michigan.
Sponges can look a lot like colonial coral, but they usually have a taller shape. I think I found all of these specimens in my uncle-in-law’s driveway.
Trilobites were bottom feeders in ancient seas. They were arthropods, which means they were invertebrates with exoskeletons and are related to other crustaceans. These are by far my favorite type of fossil. The two samples in the middle I borrowed from a friend to take photos for my presentation. The other two I purchased from an antique store and a rock shop in western Indiana. I really want to find some trilobite fossils on my own someday.
I hope these photos encourage you to go out and find your own fossils. While looking for fossils, please be aware of who owns the property where you are looking. In Indiana, it is illegal to dig for fossils on public land. Many state parks across the country have rules against taking fossils out of the park. Happy hunting!