Ordovician Galena And Maquoketa Hunt

[Caleb]

My father and I decided to take a trip to Southeast Minnesota today(9-9-2012) to try our luck at finding some trilobites. The weather was perfect, mid 70's with a nice breeze. Because of the nice weather we decided we would break rock all day. We had two sites in mind and made a quick impromptu stop at a third. Our sites were going to be first in the Prosser member of the Galena Formation and the second in the Maquoketa Formation.

The first site we hit was a fairly "new to us" site along an obscure gravel road. This was only my third visit to the site, so I'm still trying to identify productive layers. We spent a few hours splitting the limestone with little reward. After we left we made a quick stop at another cut near by for only about a half hour to check on some slabs I had set aside to wash off. While there I found a very nice complete Westonoceras sp. cephalopod.

The first stop:

Westonoceras sp.

Prosser member, Galena Formation

Upper Ordovician, Shermanian

The rest of the day we spent at a Maquoketa location, again breaking rock. I didn't find a lot in terms of numbers, but what I did find made up for it all. While venturing a little closer to the edge than I should have I spotted what looked like a tiny trilobite. I picked it up and thought I had been fooled by an upside-down brachiopod and a graptolite. Upon further examination, and a second opinion from my father, it turned out to be a trilobite! Turns out it was a ventral Cyphaspis slocomi, an incredibly rare Proetid trilobite and a first for our collection. That wasn't the only first for our collection find either! Before that I had found a large Amphilichas sp. hypostome. Now we have quite a few Amphilichas hypostomes, but this is the first one we have out of the Maquoketa Formation. I also picked up a piece of Diplograptus graptolites, a Hindia sponge and a Conulariid.

Cyphaspis and Amphlichas hypostome photos to come in the morning.

Hindia parva

Sponge

Maquoketa Formation

Upper Ordovician, Richmondian

Diplograptus peosta

Graptolites

Maquoketa Formation

Upper Ordovician, Richmondian

It was a very good day in terms of the rarity of items found, but a below average day for quantity... Though I would much rather find one rare item than many common ones. The weather could not have been better and after 8hours of swinging a 2pound hammer we left exhausted.

Edited September 10, 2012 by Caleb

[Empty Pockets]

We want the trilobite pic NOW!!!!!

[Scylla]

We want the trilobite pic NOW!!!!!

I second the motion!

[Wrangellian]

Third, but the things already shown are nothing to sniff at either!

[Caleb]

Here's the photo of the Cyphaspis slocumi. It is assigned to the family Aulacopleuridae and given the name slocumi after Arthur Slocum. We will try to get this bug flipped when prepped since it is in ventral position, and hopefully complete. It's not a perfect bug, but until now we have only found a tiny handful of cephalons and pygidiums in the decades of collecting the Maquoketa Formation.

Cyphaspis slocumi

Maquoketa Formation

Upper Ordovician, Richmondian

I'm still waiting on the photo of the Amphilichas hypostome.

[Caleb]

Here is another thing I found, but I wasn't sure it was anything until prep started. All I could see was the white weathered spot, but it looked like it could curve around... sorta. I decided to pick it up and send it home with my father so he could prep on it a bit and see what it was. My hope was a coiled cephalopod, and sure enough it was! Not only that, but it has the original shell material which is quite uncommon. Toward the tip you can see the shell pattern the best. The specimen is only about 1inch wide.

Charactoceras laddi?

Maquoketa Formation

Upper Ordovician, Richmondian

Southeast Minnesota

Here's another slightly larger specimen from the same site without all the shell material. There is a small patch of it that was preserved on the top that does show the same pattern though.

I also found a brachiopod in my pocket when checking them before washing. I had forgotten about picking it up, but it's nice with both valves. No idea on the ID since I tend to focus on trilobites.

A Brachiopod

[Northern Sharks]

Your brach looks to be a species of Plaesiomys

[Fossildude19]

Awesome finds, and report, Caleb!

Thanks for posting them.

Regards,

[Caleb]

Your brach looks to be a species of Plaesiomys

And with a little quick research, I agree. It looks like the species found in the Maquoketa is Plaesiomys bellilamellosus. Thanks!

[fossilnoob]

Nice finds! Really digging that westononcerus!

[PeterDK]

Very nice finds:)

[minnbuckeye]

Calob,

My wife and I have taken to fossil hunting over the last two years with much enjoyment. Many impressive fossils collected but we can NOT find even a remnant of a trilobite. It is a dream of my wife to find one yet this year. Any suggestions at directing us to her dream trilobite? We do live in SE Minnesota but are not opposed to travel. You seem to have a grasp of trilobites which is why I am asking u for help.

Thanks,

Mike

[Bev]

Super finds Caleb! Congrats!