A few more Mazon pieces for now

[debivort]

Here are the last of recently collected Mazon material with fossils already showing. More to come as the freeze-thaw cycles take effect. Thanks as always @Nimravis @stats @RCFossils @deutscheben @Mark Kmiecik @Runner64

 

 

 

Specimen 1 (4.1 cm long) — A fern, found as is. Enough detail for an ID?

 

Specimen 2 (9.1 cm long) — Macroneuropteris? Found as is. Did a light vinegar wash.

 

 

 

Specimen 3 (2.7 cm in diameter) — Found already split. D and E illuminated to show relief. Now that my copy of Wittry's Fauna has arrived, I wonder if this might be Essexella asherae, as there appears to be a semi-circular feature above a more rectangular feature, perhaps most visible in C and E.

 

 

Specimen 4 (~15.5 cm in diameter) — Found already split. I cannot make much sense of this. Maybe a jumble of plant pieces?  D and E illuminated to show relief. There seem to be some fossily features, like 3 or 4 repeated ridges in the bottom right of D, a long linear feature in the upper right of D (some of the material here is dirt, I realized after taking the photos). The patches of different color in B don't obviously correspond to the different relief elements in D. 
 

 

 

Edited August 11, 2022 by debivort
fix numbering

[Runner64]

I believe specimen 2 is Macroneuropteris scheuchzeri

 

I believe 3 is vegetation, especially notable in picture E.  Although it may be too worn to make an exact ID

 

4 looks like a mix of vegetation pieces, nothing looks identifiable but needs to be cleaned more.  I would suggest soaking in diluted vinegar for about an hour to start and use a toothbrush to lightly brush it.

[stats]

I agree with @Runner64.  

 

1 is Crenulopteris acadica.

 

2 is Macroneuropteris scheuchzeri.  There's not enough detail at the base to see if it's Macroneuropteris macrophylla.

 

3 looks like plant material.  Looks like a bit of bark.

 

4 is what we usually call plant mash.  I can't see enough detail. Can you take a closer photo?

 

Cheers,

Rich

 

[Mark Kmiecik]

1. Crenulopteris acadica

 

2. Macroneuropteris sp. -- I don't see the "hairs" common to M. scheuchzeri and not enough detail in the base of the pinnule to call it M. macrophylla.

 

3. Plant material -- The central portion is uneven fracturing, quite common in MC material, especially when material is preserved in multiple planes.

 

4. Lots of bits and pieces of plant material. A hash plate, also known as "floor tile" (forest floor debris). Sometimes includes bits and pieces of insects, arthropods, etc. Worth cleaning a bit with acid and checking under magnification. If nothing interesting is found additional freeze/thaw may reveal something of interest in another layer. It is common for MC material to have fossils in more than one plane.

 

 

 

Edited August 11, 2022 by Mark Kmiecik
added info

[debivort]

Thank you @Runner64 and @stats

 

Will try to clean #4 and get some close in pictures. Though I'm not sure I can get much more detail out of it. Here's a screenshot of the full resolution view of the image I posted above:

 

Here's the Essexella pareidolia I had on Specimen 3:

 

How did you all discern that it was plant material?

Were you looking at the semi-circular feature at the top, or the chunkier portion at the bottom (of C and E), or both? 

Are the parallel streaks in the semi-circular feature an indicator of vegetation?

Is plant a good default guess when the preservation of Mazon material isn't high quality?

[Runner64]

1 hour ago, debivort said:

How did you all discern that it was plant material?

 

The horizontal grain of the fossil is the most distinctive way to ID vegetation.

Are the parallel streaks in the semi-circular feature an indicator of vegetation?

 

Yes, check out this annotation of your piece, the lines indicate the vegetation piece while the circle is a fracture/weathering of the nodule caused by erosion:

Is plant a good default guess when the preservation of Mazon material isn't high quality?

No, actually, most concretions contain no fossil.  Approximately only about 1/3 of all concretions will contain a fossil (depending on where you are collecting).  You seem to have found a lot of pieces of flora, did you not find these at the Mazonia-Braidwood Wildlife Area?  If so, there is a possibility you are finding these in a more terrestrial location and would not expect to find marine organisms.

 

[debivort]

5 minutes ago, Runner64 said:

Yes, check out this annotation of your piece, the lines indicate the vegetation piece while the circle is a fracture/weathering of the nodule caused by erosion:

Thanks - this is super helpful. 

 

5 minutes ago, Runner64 said:

You seem to have found a lot of pieces of flora, did you not find these at the Mazonia-Braidwood Wildlife Area?  If so, there is a possibility you are finding these in a more terrestrial location and would not expect to find marine organisms.

Yeah - I have been surprised it's all flora so far, at least based on what I've read. Hopefully there's an animal or two in there. Almost all my material came from a private site between Braidwood and Wilmington. We also went to Tipple hill for a couple hours, but my eye wasn't dialed in / all the potential nodules I found seemed like chert, rather than siderite, so I'm doubtful of the very small number of nodules I collected there.

[Mark Kmiecik]

On 8/11/2022 at 12:46 PM, debivort said:

Almost all my material came from a private site between Braidwood and Wilmington.

That area is primarily flora with a smattering of fauna. The fauna is found south and west of Braidwood and northwest around Morris. However, the area you hunted, around Shadow Lakes (I'm guessing) produces some excellent flora and a good quantity of shark egg cases and teeth for some odd reason. 

 

 

 

Edited August 12, 2022 by Mark Kmiecik
fix typo

[debivort]

3 hours ago, Mark Kmiecik said:

However, the area you hunted, around Shadow Lakes (I'm guessing)

Yeah, I was in the section of lakes north of Shadow Lakes.

[debivort]

On 8/11/2022 at 11:49 AM, Mark Kmiecik said:

Worth cleaning a bit with acid and checking under magnification

I did an hour soak in 12.5% vinegar, soft plastic brush scrub, overnight water soak, final water soak. Here are a couple photos. If any specific features warrant closer-in photos, let me know, otherwise this sure seems like what you were suggesting: a hash plate of plant material.

[Mark Kmiecik]

I don't see anything identifiable that isn't bits and pieces of flora. Just the usual "floor tile" suspects. If it has decent thickness left for its size you can give it a few more freeze/thaw cycles and see if it splits in another plane.

[debivort]

22 minutes ago, Mark Kmiecik said:

If it has decent thickness left for its size you can give it a few more freeze/thaw cycles and see if it splits in another plane.

Great suggestion — No harm in trying and one side is still an inch or so thick.