Photos and words by Bill Heimbrock
It was below freezing that morning when we arrived at our favorite fossil site - a large road cut that exposes almost the entire Richmondian Stage of the Cincinnatian Series of formations. We had a huge turnout of members that morning. It was so cold, the mud was frozen and picking up fossils on the surface was like the old penny glued to the sidewalk trick. But that didn't stop anyone from collecting fossils.
We started on the sunny side of the road and the ice turned to mud. We were glad for that. By afternoon, the other side of the road had melted too, making some great fossil hunting.
- - Fossils Found That Day - -
Best Finds of the Day: The Mollusca
I heard one person say that they thought everyone looking for trilobites found
at least one. That is probably true, but the best find of the day was this large
coiled nautiloid cephalopod that appears to be Charactoceras baeri.
It was found in the talus from the base of the Lower Whitewater formation. It's
a really nice specimen, but began crumbling when handled. It's still in good
shape, though. (next 3 pictures)
Most of the nautiloid cephalopods we found that day were straight shelled. Here's both sides of one nice specimen.
Here's another straight shelled nautiloid that was falling apart. What remains
are the internal mold of each chamber of the orthocone.
Individual fragments of nautiloid cephalopods were fairly common as shown in the
random sampling below.
The next best find of the day was this very strange bryozoan. It appears to have
encrusted something that is completely gone now, but the original shape of the
outer shell is preserved. Our best guess at this time is that it was a
monoplacophoran called Cyrtolites ornatus. it was originally encrusted with
bryozoans, as are many Cyrtolites, but the shell did not survive. We now see
only the bryozoan taking its shape. Very interesting (next 2 pics).
Monoplacophorans are thought to be a type of mollusk. Here is another
monoplacophoran found that day. It's
Note the ornate surface.
A similar form that was found is more likely to be a snail. It most closely
resembles Trochonema madisonense.
More common were the spired snails like the two pictured below.
Another type of mollusk we found was pelecypods - specifically
the internal molds created by clam shells. Here's a picture of one showing the
hinge line to prove that it's really a clam.
This site may be the best public site in the Cincinnatian for finding
trilobites. Most people found their trilobites in the butter shale layer of the
Liberty formation. One person found at least 6 Flexicalymene sp.
trilobites. (next 3 pics)
Most people found only one trilobite, though. Here are some of the
Flexicalymene sp. found.
The above picture shows only the glabella of a Flexicalymene on a rock surface.
But this next one is pretty interesting. It looks like a burrow of a trilobite.
But it also resembles the form of a nautiloid cephalopod which shows the
Some Isotelus trilobite fragments were found too. Here's a huge but nearly
complete hypostome (mouth plate) of what was clearly a large
Some thorax segments of broken Isotelus were still
Also, the Isotelus shell segment form the genal area
were found loose and in matrix (next 2 pics).
This Indiana site is rich in brachiopods. You can collect more than a dozen varieties from this site alone if you try.
First we have examples of Lepidocyclus
perlamellosum. Some of these could actually be
We also found some individual valves of the brachiopod
We all found lots of
Strophomena sp..Note the identifiable muscle scar in the
second picture below.
Strophomena sp. were found covering
many of the slabs of rock in certain layers of this site.(next 2 pics)
Only a few Glyptorthis
insculpta were found. Here are photos of the two valves of one
nice specimen we found.
This next brachiopod, I'm not sure of the ID. I'll update my
report as soon as I find out for sure. It looks like a
This next brachiopod is easy to identify.
Rafinesquina sp. are common
throughout most of the Cincinnatian and this site was no exception.
This next Rafinesquina specimen has two different kinds of
inarticulate brachiopods attached to it. As seen in the first picture, the
larger scab-like mass is Petrocrania
scabiosa. In the second picture, we see the other type of
inarticulate - Philhedra sp..
In pockets of shale, we found bunches of the small brachiopod,
These were formerly referred to Thaerodonta.
And no trip to a Richmondian fossil site is complete without
finding at least one Hebertella sp..
Here's a sample of rock showing the huge variety of
brachiopods that are everywhere on this site.
Two basic types of coral were found on this site in the Liberty formation. Rugose solitary coral (also known as horn coral) and colonial coral.
The most common horn coral we found was Grewingkia canadensis. (next 7 pics).
The common colonial coral we found was Protaraea
richmondensis (next 3 pics).
Like all Cincinnatian fossil sites, bryozoans were everywhere.
Here is one rock with some attractive specimens of ramose (branching) bryozoans.
Ichnofossils (Trace Fossils)
Most of the trace fossils we found seemed to be presumably worm burrows. Here's
one in which the burrows seem to go in multiple dimensions in the rock.
And finally, here are some of the collecting bags people had to show with their
various selections of fossils. The Dry Dredgers stir up quite a bit of controversy
over whether to use plastic bags, cloth bags, buckets, baskets, or coffee cans
in which to collect fossils. Here is some evidence that plastic bags are
That's it for this field trip.
Now lets see how we did on our April 2015 field trip to a Northern Kentucky Kope Formation Site.
See previous field trips to this Southeast Indiana fossil mecca.
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