Carboniferous adventures in the (-A)Mazon Creek area

[khronos]

Went on a short trip to the amazing Mazon Creek Lagerstätten. I have been amazed by the Carboniferous for past decades of my life, reading research on it for the occasionally illuminating paleoclimate, stratigraphy, and evolutionary history of this very interesting period in the earth's climate for plant fossils. Which isn't to say I am not a newbie - I am a newbie, in most respects. It's interesting to think that the seeds that were growing at the time germinated in very high oxygen environments, at least the atmosphere contained 10% more oxygen than it does today (by percentage). Having more oxygen in the atmosphere, probably lowered the ignition criterion for material that was burning in the forests, where it burned hotter and with more ferocity in the tropical doldrums of the Carboniferous. Since there are many beautiful cycads growing in tropical environments, and they also have some memory-association for me with more warm and hospitable atmospheres in the southeast, like Florida, where I have visited... where palm trees grow (which came later in the evolution of plants than cycads, but are interesting nonetheless), it is natural to make the leap to seed ferns, and to have some curiosity about them. One of the seed ferns that grew in this area 300 million years ago were the Medullosan seed ferns. These produced large seeds that can be collected as petrified and nicely preserved in the Lagerstätten of Mazon Creek. Sometimes, roots are visible in the prehistoric 3-dimensional negatives of this lost world. A pollen tube can sometimes be seen.

 

 

Lepidodrendron was the predominant plant tissue throughout the carboniferous producing the large areas of coal that were used in the 18th and 19th century from Illinois, and up until present in the coal forests of the east (like in what is now the state of Pennsylvania). These plants not only produced a large amount of foliage, including the large photosynthetic bark tissue which leaves the characteristic paricnos scars in reddened coal balls, but the plant tissue known as Lepidophyllum, produced large quantities of remains in the coal strata as well.

 

I've collected some pictures of fossils I recently collected in a spoil heap of the Mazon Creek strata.

 

 

The first 4 are pictures of a petrified medullosan seed fern seed, with the nucellus still tracing some of its natural egg-yolk color (or so it seems) in the preserved tissue interior to the exoderm of the seed.

 

 

 

Followed by 2 pictures of Pleasantview sandstone, with trace remains of carbonized plant remains, likely from the depositional forces of large fires carrying these grains out to sea.

 

 

 

Followed by 2 pictures of Lepidodendron tissue in a coal ball, with paricnos scars visible, a picture of lepidophyllum tissue in a coal ball.

 

 

 

Followed by 2 pictures of petrified wood, from a Sigillaria bark.

 

 

 

 

 

 

 

 

 

The last 2 pictures are a more traditional Mazon Creek fossil, found in a concretion. This is likely of a seed fern seed, but this fossil shows some signs of root tissue, and development of a stem (not pictured).

 

[deutscheben]

I’m afraid I don’t see anything here that looks like an identifiable fossil, although some may represent indistinct plant material. Most of them are minerals or diagenetic structures that formed in the concretion. 
 

Your enthusiasm for the subject is clearly great, so I would encourage you to read more posts on this site, visit museums and join ESCONI so that you can learn how to identify Mazon Creek fossils. It can be a challenge even for experienced collectors! 

[Mark Kmiecik]

Have a look here: https://collections-geology.fieldmuseum.org/list

[khronos]

editor, "Followed by 2 pictures of petrified wood, from a Sigillaria bark." should be "Lepidophyllum in a coal ball". That's the next one after.

[khronos]

deutscheben, did you see my other post to help with ID? I took a picture of the fossils from a zoomed out perspective, so you can see a couple of the seeds I found in the sediment. The thing I labelled as cordaites seed, I now think to be a seed fern seed (pictured in the close-ups on the other side with the yellow pigment preserved). But the other seed with 3 lobes on it, near the ruler, also appears to be  Trigonocarpus, but it doesn't seem like the pictures I found online have the lemiscate-like structure.

[khronos]

the reverse side and another close-up (relatively)

[khronos]

I think the dragonfly ID is also a little extreme. I thought I could see faintly a bar on the upper wing in direct sunlight, but nothing distinct.

[khronos]

But I also wanted to show you the pollen grains in the seed, I took a few pictures of them.

[khronos]

here's a few photos of orchid seedlings from a book on orchids that look similar

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[connorp]

The upper part of the Francis Creek Shale in the area is sandstone. So your sandstone is most likely remnants of that.

[Isotelus2883]

I agree with everyone else and think that there are few identifiable fossils, except for the bivalve in the concretion identified as sigillaria bark. Your book says 1MM is the scale bar. I think the ‘pollen grains’ are rusted flecks of pyrite.

[khronos]

connorp, yes, I did read that the Pleasantview sandstone is a layer above the ironstone deposits of francis creek shale. The confusing element of the matter for me is finding a piece of sandstone with a layer of ironstone around it. How did this form if the sandstone is more recent? Was it just an older piece of sandstone? some of the carbon pieces look larger in the sandstone with the ironstone around it.

[khronos]

they look almost like needle-shaped structures of carbon in the ironstone-covered sandstone, connorp

[connorp]

32 minutes ago, khronos said:

connorp, yes, I did read that the Pleasantview sandstone is a layer above the ironstone deposits of francis creek shale.

The Pleasantview is not exposed in the area. The sandstone is from the Francis Creek Shale.

Sometimes you find concretions with a siderite exterior around a sandstone interior.

[khronos]

I am thinking now the piece I had labeled as Sigillaria stem, I meant Stigmaria, which is a part of Lepidendron. There seem to be 2 fern pinnules there as well, unless it's Lepidophyllum cut at the main vein of the leaf.

[khronos]

Does lepidophyllum have midribs/petioles?

[khronos]

The hyphae between the rhizoids in the seed I mentioned before, have pyritized blobs in them, which might mean there was sulfur dioxide present, a google search turns up this link: https://pubmed.ncbi.nlm.nih.gov/34620432/

 

Sulfur dioxide promotes seed germination by modulating reactive oxygen - species production in maize.

[Coco]

Hi,

 

Could you in the future put the links that display the photos directly on the STP forum? It would be more convenient than clicking all your links. Image hosts give a number of links, it suffices to find the right one

 

Coco

[khronos]

4 minutes ago, khronos said:

The hyphae between the rhizoids in the seed I mentioned before, have pyritized blobs in them, which might mean there was sulfur dioxide present, a google search turns up this link: https://pubmed.ncbi.nlm.nih.gov/34620432/

Sulfur dioxide promotes seed germination by modulating reactive oxygen species production in maize

 

 

 

[Isotelus2883]

5 hours ago, khronos said:

I am thinking now the piece I had labeled as Sigillaria stem, I meant Stigmaria, which is a part of Lepidendron. There seem to be 2 fern pinnules there as well, unless it's Lepidophyllum cut at the main vein of the leaf.

Again, this is likely a Mazonomya, not a plan tfragment.

[Anomotodon]

10 hours ago, khronos said:

 

 

There isn't an obvious fossil in here, aside from maybe a weirdly folded Essexella. The white stuff is calcite, you can try removing it by using vinegar and there might be something underneath it, but it's unlikely. The pollen grains you mention are likely pyrite.

 

Other pieces you label as seeds are unopened concretions, you can try freeze-thawing them to see if there is anything inside.

 

10 hours ago, khronos said:

I am thinking now the piece I had labeled as Sigillaria stem, I meant Stigmaria, which is a part of Lepidendron. There seem to be 2 fern pinnules there as well, unless it's Lepidophyllum cut at the main vein of the leaf.

 

This also looks like a Sedgwickia or Mazonomya bivalve to me.

 

10 hours ago, khronos said:

The hyphae between the rhizoids in the seed I mentioned before, have pyritized blobs in them, which might mean there was sulfur dioxide present, a google search turns up this link: https://pubmed.ncbi.nlm.nih.gov/34620432/

 

17 hours ago, khronos said:

here's a few photos of orchid seedlings from a book on orchids that look similar

 

 

 

Also, keep in mind that the references you cite here are about angiosperms (flowering plants). There were no angiosperms in the Carboniferous - they first appeared in the Cretaceous (or Jurassic, I think it's a controversial topic), and anatomy of Carboniferous seed plants (pteridosperms, cordaites, etc.) was fundamentally different. I would recommend looking into the literature specifically on Mazon Creek plants or Pennsylvanian plants in general, there is quite a lot (e.g., Jack Wittry's guide on MC flora). Or explore  numerous awesome threads from TFF members, Mazon Creek flora, Sometimes you have to whack it, etc.

[Mark Kmiecik]

There is no pollen in seeds. There is no pollen in Mazon Creek specimens because these plants existed 150 million years before angiosperms (flowering plants) came into existence. Fern spores existed, but the largest of those was no more than 120 microns in the largest dimension. The particles you refer to are monstrously larger than spores and can't be seeds. They are most likely pyrite spheres that formed much more recently since there is no recognized source of sulphur at the time of deposition of the Francis Creek Shale bed.

[khronos]

is there any evidence of mycorhizzae in the carboniferous strata around the world? That might explain the possibility of hyphae in a seed. the black dots that are around 0.8-0.9 mm in size could be some kind of mycorhizzae.

[Isotelus2883]

As Anomotodon has said, it is not a seed. It is banding in the concretion with some calcium deposits.

Here is a photo from the Rhynie Chert. The scale bars are in μm.

Edited July 22 by Isotelus2883

[khronos]

I opened a few of the concretions, and I am curious if this is some kind of bug or sea creature:

 

I also found some unidentified plant material. The rest of the mass might be petrified wood, but there is a small cellular segment