Getting My Feet Wet In the Ordovician of Wisconsin and Iowa

[RCFossils]

2018 was the year that I finally took some time to explore Ordovician aged sites in Southwestern Wisconsin and Eastern Iowa.

Inspired by past forum posts (special shoutout to Caleb Scheer who was unfortunately taken from this world way to young) along with an invite from a fellow Fossil Forum member, I was able to make several trips into the fossil rich Platteville and Maquoketa formations.

I was mainly focused on finding some of the amazing trilobites that these formations are known for. I also collected some nice representative examples of the various other fauna.

Most of my experience collecting Ordovician fossils has been in the Cincinnatian of Indiana, Ohio and Kentucky.

For those not familiar with collecting in the Cincinnatian, the vast majority of trilobites that you will find are Flexicalymene meeki along with lots of bits and pieces of Isotelus.

One of the things that struck me right away  in the Platteville and Maquoketa was the quantity and diversity of trilobite types that are readily found. While almost all of the trilobites will be fragments, occasionally you get lucky and find something complete.

There is definitely a learning curve sorting through the various trilo-bits and learning to recognize the various species.

Forum member Piranha was always willing to help out with identifications.

My first trip out was in late Winter. I spent a day with forum member Fossilized collecting a few roadcuts in both Wisconsin and Iowa. The first relatively complete trilobite that I came across that day was also possibly my rarest find of the year. It is a very rare Cheirud: Acanthoparypha sp.

Unfortunately the cephalon was gone but still an impressive specimen.

[RCFossils]

We found lots of other parts and pieces that day but nothing complete.

I did find one other amazing and unexpected piece that day.

It was my first carpoid!

I collected it in the Maquoketa of Iowa.

Thanks to forum members, I have it tentatively identified as Scalenocystites sp.

[RCFossils]

I did not make it back out again until early August.

I was camping with family and friends in Southwestern Wisconsin and decided to stop by a well known roadcut.

I only had a half hour and so made a quick search of the area.

I was not finding much as the site is heavily collected. I was getting ready to leave and took a whack at a large slab of rock. When it spit, I was shocked to see    two complete Thaleops ovata along with several partials staring back at me.

It required quite a bit of prep but it really turned out well.

[RCFossils]

[RCFossils]

[RCFossils]

[RCFossils]

In early Fall, a few friends and I ventured back to Iowa and Wisconsin. We all made some interesting finds but seemed to have more luck in the Maquoketa of Iowa.

I managed to find a tiny enrolled Anataphrus vigilans

[RCFossils]

Straight shelled cephalopods are common in the Maquoketa of Iowa. I managed to find an interesting large curved type that might be a Beloitoceras.

[RCFossils]

We were also finding some neat larger Endoceras specimens in the Elgin Member of the Maquoketa.

[RCFossils]

Here is another Beloitoceras that I collected in the Platteville of Wisconsin.

[RCFossils]

One other specimen that I collected in the Maquoketa that day was what appeared to be a poorly preserved Calymene.

i did not think much of it as it appeared to be very poorly preserved.

[RCFossils]

Once I returned home, I had a better look at this specimen. Under the oxidization, I noticed some well preserved shell material.

I had a friend of mine prep the specimen and it turned out to be a beautiful example of Flexicalymene fayettensis.

These are fairly rare and even more difficult to find prone.

[RCFossils]

[RCFossils]

I had a chance to make two more quick trips to explore the Platteville of Wisconsin.

I was lucky to find one more rare trilobite.

it is another Cheirud: Ceraurinella scoffieldi.

[RCFossils]

I also found this mystery Crinoid that still needs some prep.

[Nimravis]

Very nice finds, congrats on those beauties.

[RCFossils]

I found lots of neat parts.

This is a specimen from the Platteville. It preserves a partial cephalon and eye stalk of the bizarre trilobite Ectenaspis.

There are also two cephalons of Gabriceraurus preserved

[Roadcut1]

I’m afraid that the pictured trilobite is not an Acanthoparypha but a specimen of Amphilichas type II. There are two species found in the Platteville, this is the rarer of the two. I’d be interested in discussing it further.

[Raggedy Man]

[Tidgy's Dad]

Some wonderful finds.

Some of those trilobites are beautiful and I love the nautiloids too. 

Bit short of brachiopods, though. 

 

[piranha]

15 minutes ago, Roadcut1 said:

I’m afraid that the pictured trilobite is not an Acanthoparypha...

 

 

Here is the Russian Doppelganger Acanthoparypha,  Can you post any new specimens of Acanthoparypha that preserve the thorax or pygidium?

[RCFossils]

16 minutes ago, Roadcut1 said:

I’m afraid that the pictured trilobite is not an Acanthoparypha but a specimen of Amphilichas type II. There are two species found in the Platteville, this is the rarer of the two. I’d be interested in discussing it further.

Hi Al,

Thanks for chiming in. I would love to hear any information you may have.

[RCFossils]

8 minutes ago, Tidgy's Dad said:

Some wonderful finds.

Some of those trilobites are beautiful and I love the nautiloids too. 

Bit short of brachiopods, though. 

 

Thanks!

I have not begun to tackle the brachiopods but have some wonderful hash plates.

 

[RCFossils]

40 minutes ago, Nimravis said:

Very nice finds, congrats on those beauties.

Thanks!

We will have to get together one of these days and do some collecting.

[ynot]

That is a bunch of nice finds.

Thanks for sharing.