ON THE OHIO
When the Ohio River is low
(like it was last week near Louisville),
you can walk out on the limestone beds
at "Falls of the Ohio" State Park
and discover some of the oldest fossils
from the Devonian period of the Paleozoic Era.
That's 390-million years ago,
when the earth's first vertebrates took form,
and lived in shallow seas inhabited by
fishes, sharks, corals, ammonites and sponges.
It was a period when lung fish left the oceans
and learned to walk on the land.
This outcrop of exposed river limestone
is acknowledged as "the most famous
Devonian fossil bed in the world."
It's like walking on the bottom of the ocean
(without the ocean, of course.)