Blue Sky Science: How do scientists find fossils?

Ian Gervasi


How do scientists find fossils?

There are a number of steps that go into a researcher finding a fossil, something I spend a majority of my summer doing. First you have to figure out what kind of fossil you want to find.

You need to know the age of the rock you’re looking for, who owns the land that the rock is on, and if that rock at the surface is actually exposed.

I first consult a geologic map. This is a map where other geologists over past decades have mapped the geology at the surface of the earth.

Once I find a location with the rock I need, I then go to another map like Google Earth. Google Earth helps us determine if the rock we’re looking for is exposed. For example, we don’t want rock that’s covered with grass, or a lake, or some rancher’s pond.

Once you’ve gotten permission to be on the land, you just systematically start walking the surface looking for hints of fossils. You can walk a lot of rock and not find fossils, but you’ve narrowed the process down by doing the research with geologic maps in advance.

If you hear about a fossil dig or somebody who’s actually excavating fossils out of the ground, they usually first found it by taking the steps described above.

Fossils are also sometimes found by accident, like the mammoths that were found in Colorado recently. The mammoths were found because a crew was excavating for a house or a basement and stumbled on the fossils.

I work on fossils in the earliest part of the late Triassic period, about 230 to 220 million years ago. This is the classic red rock of the western U.S. and we spend much of our time in Wyoming.

We’re looking for some of the earliest examples of dinosaurs and the animals that are associated with them.

Each year we take a group of students from the University of Wisconsin—Madison, those that have been volunteering and working in the Geology Museum.

We got out in the field and spend two to three weeks prospecting, learning all different aspects of the science. Upon returning to the lab, the students get to work on the material that they themselves collected.