Dry Dredgers Field Trip
September 23, 2017
Northern Kentucky Scenic Byway

Photos by Bill Heimbrock

It was the first full day of autumn in Northern Kentucky. The Dry Dredgers enjoyed temperatures in the  high 70s and low 80s with plenty of sun but a nice breeze. Bob Bross and Ron Fine chose some decent road cuts along a scenic byway running east from Newport KY. The chosen sites exposed the Kope and Point Pleasant formations and hadlots of good-condition Late Ordovician Period fossils that were about 450 million years old.  The road cuts themselves have been there and weathering for at least 20 years. That's not a long time compared to how long those marine invertebrate fossils were buried, waiting for us to unearth them.

We fossil hunted for more than 3 and a half hours. That's a tribute to how much everyone was enjoying the weather and the fossils they were finding. Here are some beautiful pictures of us enjoying the fossil sites Bob and Ron picked out for us. 

Fossils Found That Day

Four sites were visited that day.I'll try to indicate on which site each of these fossils were found.

Trilobites

Trilobites are always found in this road. Here's a photo contributed by Marianne Shelton of her best find from site #4. It's a prone Flexicalymene sp. and quite nice!

Next an enrolled Flexicalymene sp. found on site #1 within 15 minutes of arrival. We were off to a great start.

Most of the Flexicalymene sp. parts we found were molted parts. Here's a glabella of another Flexicalymene sp.

And here's a very artistic and educational nautiloid cephalopod filled with silt and Flexicalymene trilobite parts!

The most rare trilobite on these outcrops to find complete but also the most common trilobite to find in parts is Cryptolithus sp, more commonly known as the "Lace Collar" trilobite. Here are some of the many lace collars we saw. (next 4 photos)

The cephalon (head) of the "Lace Collar" trilobite is much harder to find, but a few were found. (next 2 pics)

The next most abundant trilobite fragment was that of the Isotelus sp. Here's a fragment of either the head or the tail. This was a large trilobite when it was alive.

Much less common were fragments of the tiny spiney trilobites Primaspis crosotus and Acidaspis cincinnatiensis. These next 2 photos show a couple of fragments, but I can't tell which species that are.

 

Nautiloid Cephalopods

Here's one of the nicest cephalopods found that day. This is is probably part of a Westonoceras ortoni (Meek 1872). These are not common, so it's a nice find! (next 2 pics)

These next three fossils are interesting because they both show the Siphuncle very clearly. This is a tube running down the interior of the of the shell. Very cool.

We also found a lot of internal molds of the orthocone chambers of the cephalopods. (next 6 pics)

Here's a slab with lots of brachiopods and a hollowed out nautilod cephalopod. Notice the calcite crystals inside the cephalopod.

Crinoids

Some great crinoids were found on the first site we visited.

The best find was this slab with multiple calyxes. These were both Ectenocrinus simplex. (next 3 pics)

Other slabs such as the one in the next 2 photos had lots of articulated stems and looked like they might have calyxes, but they didn't.

Some rocks were loaded with crinoid stems. (next 2 pics).

Brachiopods

Both the first and second site had a layer in the Southgate member of the Kope Formation with large quantities of an unusual brachiopod. Shown in the next 2 photos below are Strophomena millionensis.

But much more abundant were very tiny brachiopods everywhere - Zygospira modesta. (next 3 pics)

Another brachiopod found in huge quantities was Sowerbyella rugosa. (next 3 pics)

In the Kope formation, it's uncommon to find the large brachiopod Rafinesquina sp. Yet we found them on site#2. The slab in the next 2 photos proves their existence alongside the lace collars of Cryptolithus sp. trilobites.  The top side in the first photo has the brachiopods and the side of the slab in the second photo has the trilobite lace collar.

Some slabs had lots of badly broken fragments of brachiopods making colorful artwork.

Graptolites

We found a layer of 3-dimensional graptolites on nodules and rock surfaces. These are spectacular specimens, preserved in pyrite and phosphate. Awesome finds! (next 2 pics).

Normally, graptolites are found preserved as simply black marks on the surface of slabs. Here's a more common slab of them we found that day. It's still interesting to the eye, don't you think?

Bryozoans

Bryozoans are probably the most common and ubiquitous fossil in our late Ordovician Cincinnatian rocks. And yet we seem to always find interesting specimens. The most interesting bryozoan was this next specimen. I think it was encrusting something, but I'm not sure what. It's shaped as if it has encrusted a Cystoid, which is a rare type of Echinoderm. Beyond that, I'm thinking there is more bryozoan underneath it.

Many of the bryozoans were growing on something that was not preserved. Here are a few of those. (next 2 pics)

This next bryozoan has high monticules - those bumps on the surface. It looks a bit like Constellaria sp. but is more likely to be Parvohallopora sp..

Gastropods

Here's a beautiful gastropod. It's Cyrtolites carinatus. It's actually classified as a Monoplacophoran.

Here's another beautiful gastropod found on the first site. It's probably a Hormotoma terebriformis.

Here's another nice snail that was partially burried. I think it's Liospira micula.

These slabs show how common these gastropods are in some layers. They are loaded with snails!

Ichnofossils (Trace Fossils)

Here's the most interesting trace fossil we found. I can't tell what made this interesting shape, because what is left is only the silt formed into a shape that resembles a cluster of worm tubes of Cornulitids. The best hypothesis I've heard so far is that it's one or more crinoid stems that were rolling around in a burrow left by some other animal. (next 3 pics)

Oddly, we found a lot of trace fossil tracks that were going around in circles. This first one was probably made by a trilobite, based on the shape of the burrow.

A couple more circular traces however, had no evidence of what kind of animal made them.

Here's a circular or disk-shaped shale object that has a burrow in the center that is filled with pyrite or iron colored shale. Originally, it was a nodule of the type very common to these specific layers.

And the next trace fossil has an interesting nickname - "Turkey Tracks." They are not made by Turkeys, it just resembles them a bit when you have a large number of these tracks. The actual cause of the tracks is still being debated.

Here's another very interesting trace fossil shown in the next two photos. The member who found it conjectured that it might be a Conularia. But it's made out of the same shale as the surrounding slab. Perhaps it's the impression of the surface of a clam. Or perhaps it's a crinoid stem rolling around on the sea floor. Purely speculation.

These next 2 photos show a burrow that has scratch marks in the bottom. Remember, you are looking at the silt that has filled in the burrow. So it's a negative impression of the burrow.

Another burrow.

This interesting slab has marks all over it.  The slab is heavily worn by weather. I can't begin to guess as to what made these marks. What do you think it was?

Bivalves (clams)

Here's a really nice internal mold of Ambonychia sp. showing both sides in the first and second photos.

This next Ambonychia sp. is preserved in a nice brown calcite.

But we also saw impressions of clams on shale surface, like the slab below. These look like Ambonychia sp. also.

And finally, to end with a "breath of fresh air." It's golden rod - loved by all - including this monarch butterfly stopping by on its migratory journey.

That's all for this trip. Hope you enjoyed it.

Back to the Field Trip Index Page

Return to Dry Dredgers Home Page

The Dry Dredgers and individual contributors reserve the rights to all information, images, and content presented here. Permission to reproduce in any fashion, must be requested in writing to admin@drydredgers.org.
www.drydredgers.org is designed and maintained by Bill Heimbrock.