Pennsylvanian fern concretion

[Peat Burns]

Hi,

 

This is an historic specimen collected in the 1870s or 1880s.  Unfortunately, it has no provenance. I suspect it might be from northern Illinois or Southern Indiana.  

 

Any help on ID would be much appreciated.  I was thinking along the lines of Lobatopteris or Pecopteris strongii?

 

 

 

[connorp]

@fiddlehead

[Mark Kmiecik]

It does resemble a Mazon Creek concretion. If I had to guess at ID, I would say it's Crenulopteris acadica. Wait for a few others to chime in though to either confirm or refute my guess. There are some places in Indiana that have concretions similar to Mazon Creek. The end that's missing was probably broken off during strip mining. Both Illinois and Indiana have been extensively mined for coal. Is it about 3-1/2 inches long?

 

 

 

Edited May 2, 2022 by Mark Kmiecik
added info

[Peat Burns]

4 hours ago, Mark Kmiecik said:

It does resemble a Mazon Creek concretion. If I had to guess at ID, I would say it's Crenulopteris acadica. Wait for a few others to chime in though to either confirm or refute my guess. There are some places in Indiana that have concretions similar to Mazon Creek. The end that's missing was probably broken off during strip mining. Both Illinois and Indiana have been extensively mined for coal. Is it about 3-1/2 inches long?

 

 

 

Thanks very much.  I see the crenulations now.  That does look like a good prospect.