New Mazon Creek Collection

[bigred97]

21 hours ago, stats said:

That is preserved chitin.  Looks like from the tail of a shrimp, like noted earlier.  Belotelson molt.

 

Cheers,

Rich

 

That makes sense, Rich - thanks!

[bigred97]

I think I will next post some specimens I found at Mazon Creek itself last summer. I found only flora which I believe is typical. When this one opened I thought it was something with legs at first (!), then quickly realized it was flora. Someone at the Esconi trip told me this is an Annularia. In the books in which I've seen Annularia it has neat whorls where the leaves all radiate very cleanly from a middle point.  This one is a little different than that so I had a harder time trying to figure out what it was. But Annularia makes sense. It seems to me this may be Annularia stellata because radiata typically has only 6-13 leaves. I think this has a little more than that, but I admit it is a little tough to count. If anyone disagrees, please let me know!

I also think this is interesting because I see what looks like different structures to this as well, although my eyes could easily be deceiving me. The part I circled below in red looks sort of like a thicker stem. The part I circled in green looks circular, almost like a nut or seed. And the part in yellow looks almost like petals, as if this were a flower, even though I know it's not (if I recall correctly no flowers had evolved by this time period). I'm fairly certain that these are all just leaves or leaf pieces that look different due to what I'm guessing is an atypical preservation. But again I would welcome any thoughts.

 

[Mark Kmiecik]

I believe that's Equisetites, sp. It's fragments of two or more segments in dorsal view with a section of stem in lateral view.

[bigred97]

Thanks, Mark!

[bigred97]

Next I'm going to post several pieces of bark I found in Mazon Creek. I have only seen specimens like this called "bark" and I don't know if there is ever a species ascribed. Perhaps not?

 

I love the colors in the first one. The fossil contains different shades of brown and the concretion itself is dark gray, almost bluish in color. The concretion itself is a little thicker than most, and the plane of the fossil was not exactly straight. I've posted a picture from the side so you can see this. It is also delicate. You will notice a slice of it came apart from the rest on one side. I suppose I could put a little super glue underneath it and reattach?

[bigred97]

Here is another example. Again, I just really like the look of these bark fossils.

[bigred97]

This one I picked up and it just started splitting into different pieces in my hands, even though I was trying to hold it gently. Thankfully it didn't totally crumble.

[bigred97]

Here is the final one for tonight. I found this as is in Mazon Creek. I can tell it's damaged but I still think it's interesting. For one thing, it doesn't seem like a concretion. It is irregular and is similar on all sides. The first picture is one side and the next picture is the other side. I also shot an angled picture to show a sense of what the whole is like. I think this is maybe a case of an entire piece of wood, but would love to know anyone's thoughts about this, or any other of the fossils I've shown. Thanks, Chris

[Mark Kmiecik]

Some of the items (40 thru 48) you posted as bark may indeed be Cordaites leaves. The last one (49) is the inner pith of a fern trunk with the outer "bark" that normally shows the leaf scars stripped away. The generic terms "bark" and "wood" are used frequently to describe MC material that is unidentifiable organic material that resembles those terms. You, me, and most others do indeed lump most items into those categories frequently. The material is abundant, so it gets brushed aside.

[bigred97]

Thanks, Mark. I hadn't thought of these as leaves but now that you mention it I see what you mean.  Chris

[Mark Kmiecik]

20 minutes ago, bigred97 said:

Thanks, Mark. I hadn't thought of these as leaves but now that you mention it I see what you mean.  Chris

Yeah, sometimes when you don't have all of the specimen present it can get confusing. Cordaites leaves are very long and slender, up to like a meter or more in length if I recall correctly. There's another long thin one called Cyperites. We used to call them sticks. I also recall the term Borassifolium being used in reference to long slender leaves but I don't see it anywhere when I Google it. 

[bigred97]

I have some Cyperites that I was planning to post next! I should have that up in the next day or two. Chris

[bigred97]

Speaking of Cyperites leaves, here are two I found in Mazon Creek.

[bigred97]

Here is another specimen from Mazon Creek itself. Until now I was thinking of this as a sort of twig. But maybe it is a part of a Cyperites?

[bigred97]

My last post for the night. I found this at the Braceville spoil pile. Is this again perhaps Cyperites, this time folded over on itself a few times? If so, I wonder what would have made it fold in such a pattern, so long ago.

[deutscheben]

I really like the last piece and the Annularia , they both have a sense of motion that you don't see in that many Mazon Creek concretions- you can imagine them drifting in a faint current. 

[bigred97]

Thanks, deutscheben! I like how you said that, I agree completely.

[bigred97]

This next one is also from the Creek but I have no idea what it is. At first glance I thought it was an interesting example of pyrite that is sometimes found within Mazon Creek concretions. But it doesn't have that silvery color/sheen to it, it is definitely white. I also thought that it looked like 3 egg casings but every example of Mazon Creek egg casings I've seen looks really different. Does anyone have any ideas? Thanks, Chris

[Mark Kmiecik]

I've never seen anything like this one before. Poorly preserved vertebrate egg cases perhaps? 

                                                                                                                                                                                                            

[bigred97]

Thanks, Mark. I find whitish blobs all the time in Mazon Creek fossils from the Braceville spoil pile or Pit 11 . But this is the only one I've found with whitish blobs from the Creek itself and the only one that has 3 distinct blobs that look to be joined. Unless anyone has other ideas, I'm going to think of this as "poorly preserved vertebrate egg cases" as you suggested. I like the sound of that better than "3 connected blobs"...

[bigred97]

Next up are some Pecopteris ferns I found at the Creek last year. I get so excited when one of these opens up, they are so beautiful! I especially like the first one, as it has a little fern in the bottom section on the side. Before this opened I wondered why it was a little fatter at one end, since I assumed it was a fern. Then it opened and I found out why!

[bigred97]

[bigred97]

Here is another Pecopteris from the Creek. I really like this one due to its unusual (in my experience) preservation. The central axis is curved in a S-shape. The plane of the fossil is also not flat - it curves, including a pronounced curve in the middle of the fossil where the angle between the two sides of the fern is extreme - it must be 340 degrees or in that vicinity. In that portion it is actually a little hard to photograph the part of the fern that is below the "lip" of the other side. Hopefully by posting enough pics it will be clearer. The concretion opened without that underlip exposed, but 2 small pieces broke away shortly after it opened as I was holding it in my hand. I tried to show how they were originally attached as well.

[bigred97]

[bigred97]

I will post two more finds that I found at Mazon Creek itself last year, then move on to posting more fossils from Pit 11 and Braceville. The first is what I think might be a partial cone bract, not a great specimen if it is but it would be the only one I've found.