Piesberg pecopterids ID help requested

[paleoflor]

L.S.,

 

Pecopterid fossils from the Piesberg (Lower Saxony, DEU) are notoriously difficult to ID because the preservation does usually not show the venation (e.g., Josten 1991; PDFs of text and atlas volume). As a group, the pecopterids have also undergone quite substantial taxonomical revisions in the last few years based on material from other localities; not in the least from Mazon Creek (Illinois, USA). This makes identification of my Piesberg-pecopteris a rather daunting endeavour. Perhaps someone on TFF who has experience with the Mazon Creek pecopterids and most current nomenclatural changes would be willing to take a stab at them for me? Images can be enlarged by clicking on them. If photos of specific details are required, let me know and I'll do my best to provide them (but note that venation is often simply not preserved very well). Thanks in advance for any ID suggestions or tips you can provide.

 

Kind regards,

Tim

 

 

 

Specimens TKTW0048 (left; "Spiropteris sp.") and TKTW0049 (right)

 

Specimen TKTW0542

 

Specimen TKTW0651 - I'm not even sure this is a pecopterid...

 

Specimen TKTW0826 (left) and TKTW0827 (right)

 

 

Specimen TKTW1004

 

Specimen TKTW1078 (left), TKTW1079 (middle) and TKTW1082 (right) - all from same slab of rock (related?)

  

 

Specimen TKTW1099  - "Spiropteris sp." but what kind of pecopterid is in the foreground?

 

Specimen TKTW1099 - note fertile pinna on the right

 

 

[FossilDAWG]

Amazing specimens as always.  It would be fantastic if @fiddlehead could take a look!

 

Don

[Mark Kmiecik]

Pecopterids are difficult to say the least. I think #651 is an Odontopterid.   #542 ?Crenulopteris acadica.   #49 ?Diplazites unita.

 

These are just guesses based on general form, robustness of the rachis and a vein or two that are almost discernable. I am less than 50% confident in these ID's. The rest I'm not even going to try. #1099 is three different species if that pointed one at the bottom is a Pecopterid, and Sphenophyllum emarginatum at the upper left, which I'm sure you already know. Good luck. I hope Jack can help with these. 

 

P.S. -- beautiful specimens.

[Tidgy's Dad]

Beautiful!

[paleoflor]

On 3/24/2024 at 7:50 PM, Mark Kmiecik said:

Pecopterids are difficult to say the least. I think #651 is an Odontopterid.   #542 ?Crenulopteris acadica.   #49 ?Diplazites unita.

 

These are just guesses based on general form, robustness of the rachis and a vein or two that are almost discernable. I am less than 50% confident in these ID's. The rest I'm not even going to try. #1099 is three different species if that pointed one at the bottom is a Pecopterid, and Sphenophyllum emarginatum at the upper left, which I'm sure you already know. Good luck. I hope Jack can help with these. 

 

P.S. -- beautiful specimens.

 

Thanks, Mark!

 

I can definitely see why you might think #651 is an odontopterid. The problem for me is the relatively strong midvein of the lateral pinnules. As far as I understand it, the pinnules of Odontopteris are characterized by lacking a clear midvein. See for example the below specimen of Odontopteris brardii from southern France. Then again the specimen also doesn't fit very well with most pecopterids...

 

Regarding the others, thanks for the suggestions and I'll see if I can make better (microscope) images of some of the pinnules that show faint venation.

 

 

 

 

 

[Mark Kmiecik]

I just looked at 1099 again and noticed that there is another species at the end of the fertile pinna. That one is a really great plate.

[paleoflor]

Took me a while, but herewith a micrograph of the sori on specimen TKTW1079. More will follow. Hopefully this helps with identification.