Unusual Carboniferous Plant Fossil

[Lucid_Bot]

Howdy! This specimen comes from the Pennsylvanian Period, Conemaugh Group, Glenshaw Formation, in the Mason Shales below Brush Creek Limestone. The area has a lot of Pecopteroids, Neuropteroids and Calamites. However, I've been informed that it is not Calamites. I should also note that this piece was part of a larger fossil cast that was crumbling apart when I found it, and unfortunately, I was unable to save the rest of it.  The last picture is the back side. All help is appreciated and thanks in advance!

 

    

[Rockwood]

Perhaps areal/trunk roots of a fern ?

[Twinwaffle]

It also kind of resembles some bryozoan images and drawings online, but maybe it could be from lycophytes outer bark ( or inner bark?) - lepidodendron, or knorria? 

FYI I'm just making a guess from some notes I took; I don't really know anything.

[Rockwood]

2 hours ago, Twinwaffle said:

maybe it could be from lycophytes outer bark ( or inner bark?)

There are aspects of the shapes and arrangement that would seem to fit. Maybe it is an unusual preservation of such a thing.

[Lucid_Bot]

It looks a bit more like calamostachys to me, but I really know anything either.

[Rockwood]

23 minutes ago, Lucid_Bot said:

It looks a bit more like calamostachys to me, but I really know anything either.

Are the protrusions (nubs) arranged in a way that crosses the axis at a right angle ? It appears to spiral more like leaf bases on a lycopod to me.

[Rockwood]

How about the core of a Lepidostrobus ?

[Lucid_Bot]

4 hours ago, Rockwood said:

How about the core of a Lepidostrobus ?

 

I think that's it! Spore cone?

[Rockwood]

15 minutes ago, Lucid_Bot said:

 

I think that's it! Spore cone?

I'll tag @paleoflor . He may see it eventually for a confirmation.

[Plantguy]

Very Neat find! Yep I thought lycopsid as well. 

 

I asked for some help from folks in the know about your specimen and got this info to ponder: 

 

At that tiny size and given its stratigraphic context it might be some kind of branch of Sigillaria, it could indeed be a cone peduncle. 

That does not rule out other possibilities. 

 

From the shape of the leaf bases, their very elongate nature, the position of the “scar” at the top of that elongate feature, and the obscurity of the leaf scar, that this thing had attached leaves and did not have leaf abscission.  This is much like seen in Stigmaria where there are scars that actually are pseudoscars – when found in situ, there are virtually always attached rootlets, but when extracted these are left in the rock matrix. 

 

No one really has studied small isoetaleans in the Paleozoic. There are a number of small lycopsids that we don’t know a lot about in compression. One is Polysporia, which becomes locally abundant following the Middle-Late Pennsylvanian floristic turnover (this is called Chaloneria in anatomical preservation).  The stratigraphic interval that includes this turnover in the Appalachians is somewhat compressed compared to the Illinois Basin and Midcontinent region, so the signal is not quite as clear.

 

Continued hunting success!

Regards, Chris 

[Lucid_Bot]

9 hours ago, Plantguy said:

Very Neat find! Yep I thought lycopsid as well. 

 

I asked for some help from folks in the know about your specimen and got this info to ponder: 

 

At that tiny size and given its stratigraphic context it might be some kind of branch of Sigillaria, it could indeed be a cone peduncle. 

That does not rule out other possibilities. 

 

From the shape of the leaf bases, their very elongate nature, the position of the “scar” at the top of that elongate feature, and the obscurity of the leaf scar, that this thing had attached leaves and did not have leaf abscission.  This is much like seen in Stigmaria where there are scars that actually are pseudoscars – when found in situ, there are virtually always attached rootlets, but when extracted these are left in the rock matrix. 

 

No one really has studied small isoetaleans in the Paleozoic. There are a number of small lycopsids that we don’t know a lot about in compression. One is Polysporia, which becomes locally abundant following the Middle-Late Pennsylvanian floristic turnover (this is called Chaloneria in anatomical preservation).  The stratigraphic interval that includes this turnover in the Appalachians is somewhat compressed compared to the Illinois Basin and Midcontinent region, so the signal is not quite as clear.

 

Continued hunting success!

Regards, Chris 

 

Very informative answer, thanks! And I just thought it was a calamite when I found it!

[Lucid_Bot]

I found another example of this fossil. In situ this time. Thought it might help confirm or deny the original ID...

[Lucid_Bot]

I should've mentioned this was found in a different location (Beaver County), but same formation (Glenshaw).