Visitors are free to stroll anywhere in Fossil Gorge, which sits in the shadow of the Coralville Spillway. — Jordan Sellergren/Little Village
Little Village Magazine has a story about Fossil Gorge in Corralville, Iowa. Fossil Gorge is a fossil locality about four hours from Chicago in central Iowa. The deposit dates to the Devonian Period about 375 million years ago... that's more than 300 million years before the non-avian dinosaurs go extinct at the end of the Cretaceous Period. The site features many Paleozoic favorites like trilobites, crinoids, brachiopods, and cephalopods. It was uncovered by large floods in 1993 and has been preserved for research and education. If you are looking for a place to see fossils this summer, give this place a visit!
The Devonian age isn’t as action-packed as the more recent Triassic, Jurassic and Cretaceous periods, which saw many-ton dinosaurs and scrappy mammaliaforms battle for survival amid massive volcanic eruptions and meteorite strikes. The period lasted 60 million years, beginning roughly 420 million years ago. Sea levels were high during the Devonian. The weather was warm and arid, the land glacierless. Earth’s first forests began sucking up carbon, depositing it into the ground.
Dubbed the Age of Fishes, the Devonian saw armored fish known as placoderms earn apex-predator status in almost every aquatic environment on the globe. Some lake-dwelling fish developed lungs and muscly pectoral and pelvic fins, eventually taking the first gloppy steps on land. These fish are the ancestors of all four-limbed vertebrates, from dinosaurs to humans.
Meanwhile, a bunch of organisms with scientific names thrived on the reef floor: brachiopods, bryozoa, hederellids, microconchids, crinoids, trilobites, bivalves, bactritoids. Now-extinct classes of cephalopods floated along in horn-like or circular, spiral shells. These ammonite fossils would appear alien — all spiky, spiny, brittle, tubular and shell-covered — if they weren’t some of the most iconic fossils on record.
