Mazon Creek Plant ID - Help?

[RoadcutHannah]

Can someone help me with an ID for this? Thank you!

[Archie]

Nice specimen! Perhaps a Pecopteris sp?

Regards, Sam

[Guguita2104]

Nice fern!!!

I agree with Pecopteris sp.

Regards,

[paleoflor]

Certainly a pecopterid (Pecopteris-like plant). However, given the lobed pinnules, your specimen may belong to a group of species that has long been grouped under Lobatopteris Wagner 1958, but has recently been under rather significant revision. See Wittry et al. (2014), where a new genus, Crenulopteris, is introduced, as well as Wagner and Alvarez-Vasquez (2016), which discusses some aspects of the aftermath. I don't know (yet!) how to properly name these pecopterid foliage elements, given all the recent changes. You may want tot contact Jack Wittry @fiddlehead via PM and provide him with a scaled image, preferably one where the nervation is visible also. He'll probably be able to help you get a more detailed ID.

[fiddlehead]

This is not a Crenulopteris. The identification can be confusing when looking at immature or poorly preserved examples like this one. A major key to distinguish Crenulopteris are the ultimate pinnae are pinnatifid, or to put it another way, they do not form individual pinnules. They are only partially separated and are lobed or crenulated. This example clearly has separate pinnules as seen, starting in upper right fifth pinna. This occurs a relatively short distance from the distal end of the penultimate pinna. And indicates the fully mature pinnules will be fully separate and well defined. As to what you tentatively have, based on just the gross morphology is Pecopteris oreopteridia. It has the larger proximal pinnules especially on the lower side and rather distant ultimate pinnae. Both these features are characteristic of this taxon.

 

Hope that helps,

Jack