Educator Handbook: Natural History of the FallsNatural History of the Falls of the Ohio Natural History
The history of the Falls of the Ohio reaches back millions of years, leaving us with a wealth of natural wonders and resources to explore. They include 390 million year old Devonian fossil beds, a variety of flora and fauna including over 270 species of birds and 125 species of fish, habitats and interesting geological formations such as sculpted limestone, natural arches and small waterfalls.
The formation of the Falls fossil beds dates back to the middle of the Devonian Period (in the Paleozoic Era) between 408 - 360 million years ago. At that time a shallow sea cut diagonally across the eastern half of the North American continent from New York through Kentucky south and west over Texas. The Appalachians and the Great Plains were above sea level.
Devonian sea life diorama The branching coral Alveolites The continental sea was teeming with a variety of marine life including fish, echinoderms, trilobites, brachiopods, bryozoans, sponges and corals. The skeletal remains (mostly calcium carbonate) settled on the sea floor, steadily burying older layers of sediment. Over time the sedimentary rock limestone was formed, which preserved the fossils.
During the remainder of the Paleozoic Era, this area was alternately under a sea, swamps or intermittently exposed as land. During the Mesozoic Era (the “Age of Dinosaurs”), the area was land (with dinosaurs everywhere). The evidence of dinosaurs was not preserved, because there were no rocks formed in the area during the Mesozoic. Except for a brief time when the Gulf of Mexico inundated the Mississippi Valley as far north as Jackson's Purchase in Western Kentucky, land was eroding away, as it is today.
Millions of years later during the Pleistocene epoch, glaciers advanced from the north. Over a period of two million years, they helped form the present day Ohio Valley. The last glacial advance (the Wisconsin glaciation) ended about 12,000 years ago. The last glaciers pushed south stopping more than 60 miles north of the Falls before melting. This melt water, coupled with millions of tons of loose rock filled the river valley and shaped the river we call the Ohio. Once the glacial meltwater stopped flowing into the Ohio Valley basin, the river became the size it is today, and as the river was perched on the north side of the valley (its present location), it became 'stuck' on top of the fossil beds. The Falls are somewhere between 8,000 and 10,000 years old - which in geological terms was just yesterday!
The Devonian limestone extends to the north beyond Indianapolis, Indiana, and southeast to the Cumberland plateau. It may be found in northern and central Ohio and swings into Canada and over to western New York. It also occurs in southwestern Illinois and into central Missouri. During the Devonian, the North American and African continental plates were not far apart. Fossils similar to those at the Falls can also be found in Morocco, in northwest Africa.
These fossil beds are considered to be among the largest naturally occurring laterally exposed Devonian coral beds in the world. Over 300 species of fossils have been identified at the Falls, many of which are type specimens, being discovered and described from the Falls for the first time.
The fossil beds are only one natural resource at the Park. There are over 270 species of birds recorded, including shore birds, wading birds, and song birds. There are several endangered species which visit the Falls - the American Bald Eagle, the Osprey, two species of Night-Herons and the Peregrine Falcon. Cormorants, herons, gulls, geese, ducks, egrets, loons and kingfishers may be seen. White-tailed Deer on fossil beds Immature Black-crowned Night-Heron The Falls have been used as a fishing area for thousands of years. Some 125 species of fish have been reported. Some of the largest are catfish, weighing over 100 pounds. Three of the oddest fish, the long-nose gar, the paddlefish (spoonbill “catfish”) and the shovel-nose sturgeon resemble prehistoric fish.
Other fauna which may be seen at the Falls include mammals like the fox, white tail deer, beaver, eastern cottontail, gray and fox squirrels, muskrat, opossum, and raccoon. Reptiles including turtles, lizards and non-poisonous snakes may be rarely seen. Invertebrates including river mussels, snails, and a variety of aquatic and airborne insects can be observed.
Flora at the Falls include both native and non-native species. Evening primrose, prairie mimosa, monkey flower, wood sage, bittersweet nightshade and tickseed sunflower may be seen blooming at various times. Trees include the eastern cottonwood, sycamore, black willow, honey locust, silver maple and Osage orange. Other plants include star cucumber vine, sumac, trumpet creeper and bind weed. Sensitive Plant Cassia nictitans Indigo Bush Amorpha fruticosa The flora and fauna flourish at the Falls in a variety of habitats including river, stream, wetland, mud flat, sandbar, marsh, prairie, rock, and woodland. These diverse habitats coexist in a concentrated area that has been altered both by man and nature.
The diversity of the natural resources at the Falls provides an unlimited opportunity for study and simple enjoyment of a “natural” area rich in biodiversity. ix-x. Cultural History Created January 22, 2010, Updated March 20, 2012 |
