Fern Fossil New Mexico?

[iliafes]

It is from New Mexico, likely from Pennsylvanian formations.  Is it a fern? 

[paleoflor]

7 hours ago, iliafes said:

It is from New Mexico, likely from Pennsylvanian formations.  Is it a fern?

This seems to be some sphenopterid foliage. Since Sphenopteris-like fronds were borne by both ferns and pteridosperms, it is not possible to say whether this is a fern without a species-level identification. Unfortunately, this is quite challenging for these 'fine, delicate fronds', especially on the basis of a photo. What is the size of the specimen?  

[iliafes]

This part of the plant is 2 cm long. I cannot spot on the web any fossil similar to this fine structure.

[iliafes]

Maybe this is similar:

http://www.fossilmall.com/EDCOPE_Enterprises/plants/plfossil44/plant-fossil-44.htm

 

[FossilDAWG]

The fossil you linked is from the Cretaceous of China; the great age difference makes it likely that any similarity is superficial.  As paleoflor said, very distant plants (taxonomically speaking) share foliage of this type.  We might be able to narrow things down some if we had more information about the locality where you found this fossil.  For example, similar material is known from the Kinney quarry in the Manzanitas Mountains.

 

Don

[iliafes]

I bought it in Mamas minerals and I only know that it is from NM. It is very similar to Sphenopteridium manzanitanum from the Kinney quarry 

Ref Fig 22: https://www.researchgate.net/publication/237842451_An_update_on_the_flora_of_the_Kinney_Quarry_of_central_New_Mexico_Upper_Pennsylvanian_its_preservational_and_environmental_significance

 

[paleoflor]

The very small size of the pinnules in your specimen (which is 2 cm long in total) does not fit with Sphenopteridium manzanitanum (see scale bars in Figure 22 of DiMichele et al., 2013). The pinnules of S. manzanitanum also are lobed, whereas the ones in your specimen are more acutely pointed. Given the very small size, you might want to compare your specimen with Zeilleria (e.g. Z. deliculata, Z. frenzlii, Z. hymenophylloides). Note that the similarities are quite superficial, however, and that there are definitely many more, similar-looking forms. Confident identification would require specialized literature, preferably dealing with your locale. Personally, I'd therefore stick with Sphenopteris sp. for now.

[iliafes]

Zeilleria have almost right angle between the leaflets and central rib, but my specimen has almost 45deg.  

[Fossildude19]

It reminds me of some specimens of Rhacophyllum sp.