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Late Pennsylvannian Finds From Lost Creek Jacksboro Finis Shale


mikecable

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I hope I'm not overstepping my place on the Fossil Forum by starting this topic. Like bobwill, I've become fascinated by the Finis Shale at Lost Creek, after just two trips. Both trips were very muddy, but I'm still amazed by the variety of fauna represented at the site.

We had the privilege of meeting the illustrious, infamous and famous Roz at the end of our last visit. When you have "Rozilla" emblazoned across your rear window you have to expect that people might make a connection to the Fossil Forum. The "I'd rather be in the Cretaceous" bumper sticker was just the clincher. But this topic has been inspired by bobwill, Lance, Dan, erose and many others as well.

I'm not trying to usurp, step on, or over-ride anybody's topic on the the Finis Shale. Which doesn't mean I don't have my own self-serving interest in starting this topic.

I'm new to this, and especially new to identification. I've spent the past several days of my spring break sorting and attempting to ID some of the fossils I've found at Lost Creek. I've sorted, and resorted the fossils I've found. I've compared them to posts by bobwill and others. I've searched Pennsylvanian Fossils of North Texas by McKinzie and Mcleod. I've double-checked with Lance's http://northtexasfossils.com site. I'm learning how to use Index Fossils of North America by Shimer and Shrock, and Invertebrate Fossils by Moore, Lalicker and Fischer. So I'm trying to learn to become more than the "guy who picks up neat fossils."

I'm also trying to engage my sixth grade science students. They become more involved when I can make it real for them. My collecting trips and ID efforts excite them. When they see a topic like this one, they see me as a scientist engaging with other scientists. Which is largely true.

As much as this site has been publicized on this forum, and others on the Internet, I don't see the site being over-hunted. Our first trip there we were by ourselves. Our second excursion involved Roz, and another couple of hunters showing up. I can't imagine how even a hundred-fold hunters could truly over collect this site.

I'm sorting duplicates to either allow the kids to sort and take home, or to present a collection for the next forum auction. I've taken out about two gallons of matrix to either sort for myself, or to trade for other micro matrix.

Finally, I'm practicing my photo skills with limited equipment.

So let's begin.

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Lophophylidium proliferum

Grabau 1828

coral

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I hope I'm not overstepping my place on the Fossil Forum by starting this topic...

This is your Forum, Mike, and we appreciate what you bring to it! :)

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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BobWill has identified these as Hystriculina texana. Lance stays conservative with Marginifera sp?

I can't find any good evidence to argue with either one of them. The example I've shown depicts a difference. One example is more triangular, with a lower brachio crown. The other is much more rectangular. But as I sort the specimens, I keep moving examples from one column to the other. This example fascinates me.

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BobWill has identified these as Hystriculina texana. Lance stays conservative with Marginifera sp?

I believe 'Marginifera' is one of those old-school, catch-all names for a general form that has since expanded into several genera. I'd say it's still valid to use as a preliminary id, unless 'Marginifera' has been retained for a specific form.

Context is critical.

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I believe 'Marginifera' is one of those old-school, catch-all names for a general form that has since expanded into several genera. I'd say it's still valid to use as a preliminary id, unless 'Marginifera' has been retained for a specific form.

This is what I would like to know. I'm having a hard time making the difference from old-school and new-school.

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http://www.thefossil...ttach_id=140346

Here Bob Will has identified a specimen as Cladochonus--I think mine to the right may be Cladochonus based on the irregular branching.

Lance Hall has a specimen on his site identified as syringopora--I can't link directly to the image. While the branches are irregularly spaced on my specimen to the left,, they do appear to be growing roughly parallel--which leads me to ID this specimen as syringopora.

Any thoughts?

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Composita ? ovata

It's not readily apparent in this pic, but there is a will-developed fold and sulcus on the anterior.

post-7463-0-01616600-1332010467_thumb.jpg

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post-7463-0-37633800-1332011275_thumb.jpg

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Phricodothyris perplexa or Cleiothyridina orbicularis?

I'm basing either of these possible IDs on Lance's web page. His example of Phricodothyris perplexa came from the Salesville Shale at Mineral Wells, rather than the Finis Shale. But Lobza, Shieber and Nestell describe examples of Phricodothyris perplexa as coming from the Finis Shale.

I only found the one specimen like this, but it is very well preserved.

Thoughts?

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Fantastic fossils Mike... Thanks for posting :D

I've only been to the site twice, but the variety and quality of preservation amazes me. It seemed that every time I went to pick up my pack or staff there was some tiny jewel right beneath my hand. I haven't really touched the medium or fine micro-matrix yet.

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Gonioloboceras Teichart 1940

based on Bob Will, and McKinzie and McLeod. Mostly from the zig-zag pattern of the suture lines.

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Tabulipora sp? encrustation.

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Unknown bryozoan.

The bryozoan looks like a Polypora to me..

Welcome to the forum!

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The bryozoan looks like a Polypora to me..

I'm pretty sure you are right, but I want to see more examples in hand to say anything definitive.

It was my pleasure to meet you in person the other day at Jax. I feel confident we will get to collect fossils together at some point in the future. I'm looking forward to the occasion, and looking forward to meeting Lance as well.

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A small hash plate that has several silicified small brachs. I've got a number of them weathered out as well. I'll post the individual specimen pics later. But I don't have a clue.

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My hunting partner Gary sees more coprolites than I do out of this formation. But I do see a coprolite here. Yes?

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Micro-matrix from immediately beneath the top limestone layer. Rich in fusinilids.

Fusinilids are super cool.

Until you see nothing but fusinilids. Then they are just cool.

When that is all you find in the matrix, then they are just fusinilids.

  • I found this Informative 1
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http://www.thefossil...ttach_id=140346

Here Bob Will has identified a specimen as Cladochonus--I think mine to the right may be Cladochonus based on the irregular branching.

Lance Hall has a specimen on his site identified as syringopora--I can't link directly to the image. While the branches are irregularly spaced on my specimen to the left,, they do appear to be growing roughly parallel--which leads me to ID this specimen as syringopora.

Any thoughts?

I think, possibly like yours, my ID was based on the differences in the photos on pages 80 and 61 of McKinzie and McLeod. They are very similar. I'm taking my display boxes to the DPS meeting Wednesday for some help with corrections and additions to my IDs so I'll post if I'm wrong on any of these. I usually defer to Lance since he has so much more experience but I didn't see a Cladochonus on his site.

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BobWill has identified these as Hystriculina texana. Lance stays conservative with Marginifera sp?

I can't find any good evidence to argue with either one of them. The example I've shown depicts a difference. One example is more triangular, with a lower brachio crown. The other is much more rectangular. But as I sort the specimens, I keep moving examples from one column to the other. This example fascinates me.

Not to muck things up... but I believe these are Retaria lasallensis (Worthen). That is based on size (larger than Hystriculina) and several other ID sources such as Index Fossils of North America.

I am extremely frustrated by what should be a great ID reference: Texas Pennsylvanian Brachiopods, Herbert et al., 1990, HGMS. For many of the listed species the book is fine but for some the drawings and descriptions are really lacking. AND as always the stratigraphic data is dubious. It's still one of my first references but it also sometimes leaves me even more in doubt. For you beginners and intermediates THIS is why us old farts suggest getting your hands on as many books and papers as possible.

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I'm pretty sure you are right, but I want to see more examples in hand to say anything definitive.

It was my pleasure to meet you in person the other day at Jax. I feel confident we will get to collect fossils together at some point in the future. I'm looking forward to the occasion, and looking forward to meeting Lance as well.

It was great meeting you, Mike. I enjoyed our fossil chat and I am sure we will hunt again. You missed Lance by one day on that hunt.

Welcome to the forum!

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Not to muck things up... but I believe these are Retaria lasallensis (Worthen). That is based on size (larger than Hystriculina) and several other ID sources such as Index Fossils of North America.

I am extremely frustrated by what should be a great ID reference: Texas Pennsylvanian Brachiopods, Herbert et al., 1990, HGMS. For many of the listed species the book is fine but for some the drawings and descriptions are really lacking. AND as always the stratigraphic data is dubious. It's still one of my first references but it also sometimes leaves me even more in doubt. For you beginners and intermediates THIS is why us old farts suggest getting your hands on as many books and papers as possible.

Thanks much for this clarification erose. The differences in some of these always bothered me. For example, in the 2 samples above the one on the left is more square and the right one more triangular. The right one is also smaller which makes me wonder if it could be Hystriculina and the left one Retaria. At least Lance had the wisdom to use the family name which covers them both.

Bob

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