Think of Florida rivers and creeks as time machines,
offering direct access into the past.
They perform the same work as a shovel, cutting
down through the sediments. Year after year, rainy
season after rainy season, fossils are flushed out
of the banks and river bottoms by flowing water.
Other fossils are covered up as sand and silt is moved
from one area to another.
Animals have always lived near rivers to drink, making
them easy targets for human and animal predators. If
parts of their skeletons were washed into a river, or
dragged in by alligators, it's a good bet that whatever
wasn't consumed would be carried off by the current
and eventually sink.
If an animal died in a swamp, parts of the body might
also be buried quickly in the soft material by its own
weight. Later, a river might form and plow
through the wetland-uncovering the now fossilized bones.
Once a skeleton is covered and protected by sand, mud
or clay, oxygen and bacteria are unable to reach the
bones. However, Florida's abundance of minerals,
including carbonates and silicates, are able to
penetrate the bones. The preservation process starts
immediately in Florida. Destructive elements, such as earthquakes, volcanoes, or the shifting of tectonic
plates-have not been present here over the last 30
million years. We have had hurricanes, but they tend
to do much more damage along the coastline than inland.
These "calm" conditions are ideal ingredients for
fossilization to occur. The exception to these calm
conditions were rising oceans throughout various ice ages.
In the last two million years alone, Florida has been
covered by ocean at least 24 times. If the water rose slowly
enough to keep moving the surf inland, a lot of fossils
would be broken up in the process. But the oceans didn't
always rise rapidly or destroy large pockets of marine and
terrestrial fossil deposits in the process. That is until
rivers and creeks came along. Now, all we have to do is
understand them. Which ones contain fossils? Are they
shallow enough to screen-wash or snorkel, or do we need
SCUBA gear? What time of year is the water too high?
When is it low? What dangers are present?
Alligators? Snakes? A strong current? Bacteria in the
water?
The first thing you should know about Florida rivers and
creeks is that every one of them is different. The more
you know about their unique personalities, the better your
chances are for finding great fossils. With over 1700
creeks and rivers in the state -- 40 of which are major
waterways -- the opportunities are limitless. Flip through
the following pages and see what we're finding, not just
in the waterways, but on dry land as well.