Kentucky Fossils: The Falls
of the Ohio
by Gene Everson
The world's largest Devonian
fossil outcropping is The Falls of the Ohio, located at Louisville,
Kentucky. A wonderland of long extinct rugosan fossil corals,
brachiopods, trilobites, crinoids and primitive mollusks, the
Falls is a mecca for fossil fans the world over.
The "Falls" are actually
cascading rapids, dropping 26 feet in a 21/2 mile stretch of
the Ohio River. Four hundred million years ago, the area where
the Falls of the Ohio is today was covered by a shallow, tropical,
inland sea. Within this huge sea vast numbers of corals thrived,
and the most highly evolved life forms on earth were primitive
fish like the earliest sharks and the armor-plated Dunkleosteus.
During Devonian times, before the shifting of the continental
plates to their present position, this area was 20 degrees south
of the Equator, accounting for its tropical marine fauna. Colonial
corals like Favosites were encountering competition from the
many evolving types of solitary rugosan or "horn"
corals (Zaphrenthis, and others). Carnivorous cephalopods, in
coiled or uncoiled shells, flourished in this sunlit sea, hunting
in the shallow beds of brachiopods and primitive bivalves (Paracyclas),
and among the multiform trilobites of the time.
At the end of the Devonian, this
inland sea and reef ecosystem was doomed by the collision of
two tectonic plates, which drained the shallow sea. The fish,
the corals and other sea life died, to be buried in layers of
lime silt and sediments that caused them to become fossilized.
They remained hidden in the earth for hundreds of millions of
years until, during the retreat of the ice age glaciers of the
Pleistocene, rushing meltwater carved out the Ohio River Valley
and exposed the Devonian fossil beds. The resulting exposure
provides a unique view of an ancient coral sea floor preserved
in stone. Today the Falls of the Ohio is recognized as a valuable
resource and is protected as a State Park and a world historical
Falls area facts:
- More than 600 species of
fossils have been found there; for two-thirds of them, this
is the type locality.
- The primitive paddlefish is
one of the 125 species of fish found at the Falls. Two of
these unique paddlefish are currently on display swimming
in one of the Interpretive Center's aquariums.
- More than 265 species of birds
have been recorded at the Falls.
- John James Audubon made more
than 200 sketches of birds while living in the Falls area.
- Mark Twain and Walt Whitman
both wrote about the Falls of the Ohio.
- In 1778, George Rogers Clark
founded on Corn Island at the Falls the first permanent English-speaking
settlement in the Northwest Territory.
- William Clark, younger brother
of George Rogers Clark, set out from here with Meriwether
Lewis on their mission to explore the territory of the Louisiana
After several attempts to preserve
and protect the area, the 20th Indiana State Park was established
in 1990. Now, fossil, rock and mineral collecting is prohibited.
Tours are available and the Falls of the Ohio now has a unique
Interpretive Center: its exterior, constructed of many layers
of different brick and stone colors and textures, suggests a
The 1999 COA Convention in Louisville
will sponsor a mid-convention field trip to the Falls of the
Ohio on Tuesday, June 29. The Park is a mere 10 minutes away,
just across the Ohio River from the Galt House, our convention
hotel; its unusual Interpretive Center is visible from the hotel.
in the December 1998 issue of American Conchologist.