My Mazon Creek Finds

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On 9/23/2019 at 5:02 PM, Mark Kmiecik said:

 

I'm afraid this Essexella looks more like a poorly preserved fish scale to me. Can you see the outline? Here's one previously posted on TFF.

 

 

Thanks Mark- I wish it was a fish scale, I have not found one here yet! Unfortunately in close examination it does not have any of the right texture, though. 

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3 hours ago, bigred97 said:

Very nice finds! I really like the Mazopherusa, I don't think I've found one that nice yet. And maybe the Essexella is actually a new species - a "lightning jelly"! Good way to market it online haha.

 

I have horrible luck with the bivalves, they all seem to crumble to pieces. I can't ever get one that just splits cleanly. I suppose it's probably because the fossil plane is not flat. I have several piles that I might try to superglue back together sometime.

Thanks! I have the same problem with bivalves from Braceville. I find they are preserved much better from Pit 11 and Chowder Flats- I think the only ones I have kept from Braceville are tiny. 

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I had 4 new Essexella jellyfish in 2 nodules split over the last few weeks- that's 2 sets of pairs! The first is from the Braceville spoil pile- the two jellyfish are actually on slightly different overlapping planes in the concretion as you can see by the shadow running down the middle. There is also some scrappy plant material preserved with them. 

 

 

The next concretion came from Pit 11 and actually split twice to reveal the two Essexella- the second one much smaller than the first.

 

 

 

So far this is my only decent Pit 11 split- every other concretion has been a blank, except for a few small poorly preserved jellies. 

[Mark Kmiecik]

Nice finds. Much better luck than I ever had at Pit 11 except for one small area that was loaded with Essexella.

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Thanks @Mark Kmiecik! I am actually wrapping up processing my Pit 11 finds from this spring, with only a handful that have not yet split with freeze-thaw or a few taps of the hammer. In the end it was not a super productive year in terms of quantity, with I think only 13 concretions producing anything identifiable out of about 1 gallon found. On the other hand, one of those finds was my first Tully Monster, so I would still say it was a successful year! My tally for the year at this point is 2 worms, 2 shrimp, 6 jellyfish, 1 indeterminate plant material, 1 coprolite and 1 Tully. 

 

I had one more large Essexella with some nice definition split. 

 

 

And finally a tiny and delightful surprise, one that was so subtle I almost overlooked it. This is the rare shrimp Essoidia epiceron, displaying its characteristic s-shape. Its a new species for my collection, too, which always makes me happy to find. Unfortunately my phone camera had a little trouble focusing, so the pictures are not as clear as I would like. 

 

 

[RCFossils]

53 minutes ago, deutscheben said:

Thanks @Mark Kmiecik! I am actually wrapping up processing my Pit 11 finds from this spring, with only a handful that have not yet split with freeze-thaw or a few taps of the hammer. In the end it was not a super productive year in terms of quantity, with I think only 13 concretions producing anything identifiable out of about 1 gallon found. On the other hand, one of those finds was my first Tully Monster, so I would still say it was a successful year! My tally for the year at this point is 2 worms, 2 shrimp, 6 jellyfish, 1 indeterminate plant material, 1 coprolite and 1 Tully. 

 

I had one more large Essexella with some nice definition split. 

 

 

And finally a tiny and delightful surprise, one that was so subtle I almost overlooked it. This is the rare shrimp Essoidia epiceron, displaying its characteristic s-shape. Its a new species for my collection, too, which always makes me happy to find. Unfortunately my phone camera had a little trouble focusing, so the pictures are not as clear as I would like. 

 

 

I would agree that is an Essoidia!

Nice find

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I've also had some more concretions from the fall 2018 ESCONI Braceville trip split, including this lovely little Essexella. 

 

 

And this slightly squashed Achistrum sea cucumber. 

 

 

As well as a number of fan worms, but the lighting needs to be just right to photograph those, so I will have to post them later. I now have my last concretions from this trip rotating through the freezer.

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15 minutes ago, RCFossils said:

I would agree that is an Essoidia!

Nice find

Thanks! And thank you for the ID confirmation.

[RuMert]

Nice finds! But where is the Tully?

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3 minutes ago, RuMert said:

Nice finds! But where is the Tully?

A very good question! I only posted it in my trip report from this spring http://www.thefossilforum.com/index.php?/topic/93062-3119-mazoniapit-11-opening-day/ but here it is again for those who didn't see it:

 

 

[RuMert]

Very nice! Open concretions collection pays off. No need to wait by the freezer to find nothing

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For sure, it's good to get a reward at the beginning of the process. (Although honestly, being outside collecting fossils is a reward of its own). 

 

Here are a few more of those sparse Pit 11 splits I had this season. First is some indeterminate plant material, in a nice red color though:

 

 

Next is what I think is a small partial Archisymplectes rhoton worm. 

 

 

And finally a little squiggly something- my first thought was coprolite, but I suppose it could be a very tiny juvenile sea cucumber? 

 

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Here are a few more Mazopherusa fan worms from the 2018 ESCONI Braceville trip. The first shows two partial worms:

 

The next has a lot of mineralization- white powdery calcite around the edges and a gold crystal in the middle- probably pyrite? It's also unusual in that it appears to preserve the impressions of some finger-like projections from the front of the body that aren't the typical thin bristles. They could just be preservational artifacts, or it could be the gills as seen on this page about the modern fan worm Pherusa http://micksmarinebiology.blogspot.com/2016/10/pherusa-plumosa-short-study-of-plume.html?m=1.

 

 

Finally, this third concretion actually split twice, revealing a worm on both sides. Unfortunately, it's preserved in a way that is extremely hard to photograph- most of the fossil is only visible when it is wet and held at just the right angle, otherwise all you can see is some scrappy black where the body is. I was able to capture one side well enough so you can see the outline of the worm including some projections extending from the front (top) end as well. 

 

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I have also found a few interesting shells. I believe the first one is my second example of the branchiopod (clam shrimp) Pemphilimnadiopsis ortoni (what a generic name!). 

 

 

Next is what I think is an uncrushed example of the bivalve Myalinella meeki.

 

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I am happy to be able to report my first find of a shark egg case from the Braceville ESCONI site- actually my first from any Mazon Creek site. I have found a few Palaeoxyris prendeli from sites in east central Illinois and west central Indiana, so this partial Paleoxyris lewisi is also a new species for me.

 

 

I also had this 3-D trace fossil of a tunnel of some sort split:

 

 

As my unsplit Braceville and Pit 11 concretions have thinned out (I only have about 15 and 6 left, respectively), I have been soaking the 4 gallons of Chowder Flats concretions in my garage and starting to run them through the freeze-thaw cycle too. Other than a few pieces of indeterminate plant material, the first one to split was this mysterious object.

 

 

From the texture and shape my first guess would be a fish scale, but I think it could also be some kind of crustacean material? It would be exciting if it was a scale, since I do not have any in my Mazon Creek collection yet. Unfortunately, the top third is still covered by rock and I'm not sure how well it will prep out. 

[bigred97]

Congrats on the Palaeoxyris prendeli !!!  Great find - congrats! Such an awesome feeling when you see that split in the concretion and you are about to open it and it could be anything, but usually is nothing. And then it's something like that - so exciting!

[deutscheben]

3 hours ago, bigred97 said:

Congrats on the Palaeoxyris prendeli !!!  Great find - congrats! Such an awesome feeling when you see that split in the concretion and you are about to open it and it could be anything, but usually is nothing. And then it's something like that - so exciting!

Thanks! I agree it is a thrill every time something identifiable pops open. 

 

I spent some more time looking at the "fish scale" and comparing it to documented Mazon Creek scales and I think I was wrong- it doesn't quite match up. Another Mazonian mystery it seems...

[Mark Kmiecik]

1 hour ago, deutscheben said:

Thanks! I agree it is a thrill every time something identifiable pops open. 

 

I spent some more time looking at the "fish scale" and comparing it to documented Mazon Creek scales and I think I was wrong- it doesn't quite match up. Another Mazonian mystery it seems...

It's not a fish scale. I'm getting an insect/arthropod/crustacean vibe from it, but I'm really good at misidentification of MC fauna. It looks similar to the second photo.

 

Nice Palaeoxyris prendeli .

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I think you set me on the right track, @Mark Kmiecik, I was able to find some earlier posts with something similar that was ID'ed as a piece of shrimp carapace. 

 

My Chowder Flats concretions have gone through a number of cycles now and are starting to split regularly. Here are a few of the more interesting finds. 

 

First is a faint Achistrum sp. sea cucumber. The only clearly visible part to the naked eye is the oral ring. However, under magnification the hook-shaped sclerites are very clear and distinct- this is my first specimen where that is the case. Unfortunately I don't have a camera that can capture them. 

 

 

Next is another variation on the most common Essex biota fossil, the jellyfish Essexella. This one contains the most jellies in one nodule of any in my collection-  a real riot! I think there are at least 9 or 10 preserved here. 

 

 

The jellyfish I find at this site are consistently smaller than those I find from Pit 11- the largest is less than 5 cm tall, with many in the 2 cm range, while Pit 11 ones are regularly 10 cm or more. 

 

Finally, true to the name of Chowder Flats, I have been finding a fair number of bivalves. In addition to some poorly preserved examples of the most common species Mazonomya mazonensis, I also found a new species for my collection, Palaeolima retifera. Only one valve is preserved, and the counterpart of the concretion crumbled away, but it's still a perky little shell I am glad to have. 

 

 

[Mark Kmiecik]

Nice. I count 10 jellies. My best is a two-fer.

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On 12/22/2019 at 4:25 PM, deutscheben said:

As my unsplit Braceville and Pit 11 concretions have thinned out (I only have about 15 and 6 left, respectively), I have been soaking the 4 gallons of Chowder Flats concretions in my garage and starting to run them through the freeze-thaw cycle too. Other than a few pieces of indeterminate plant material, the first one to split was this mysterious object.

 

 

From the texture and shape my first guess would be a fish scale, but I think it could also be some kind of crustacean material? It would be exciting if it was a scale, since I do not have any in my Mazon Creek collection yet. Unfortunately, the top third is still covered by rock and I'm not sure how well it will prep out. 

I have something similar from the garage sale this past summer and fall.  I believe it is from Morris.  Here is the picture... looking for an id.

 

 

Cheers,

Rich

 

[stats]

17 hours ago, stats said:

I have something similar from the garage sale this past summer and fall.  I believe it is from Morris.  Here is the picture... looking for an id.

 

 

Cheers,

Rich

 

 

I spoke with Jack @fiddlehead last night at the ESCONI Paleo meeting.  He said this is part of a Beletelson shrimp, which would have been a pretty good sized one. @deutscheben yours looks similar.

 

Cheers,

Rich

 

[deutscheben]

Thanks for the update! 

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Continuing with the Chowder Flats bivalve theme, here is a tiny Aviculopecten mazonensis, my smallest and most complete yet. 

 

 

Next is a worm of some sort- I think it is Paucijaculum samamithion? I only have one half of the concretion though. 

 

 

 

And finally this third one that I do not feel confident about an ID for. The general shape, preservation, and asymmetrical  dark stains lead me to think it might be an incomplete example of the jawless fish Gilpichthys greenei. I could also see it being an oddly preserved worm of some sort, though. 

 

[deutscheben]

Another partial Paucijaculum split for me this week- happily this one has both sides of the concretion.