Lepidodendron or coral?

[Micah]

While I was looking at a recent post here on the forum trying to help someone identify a Lepidodendron tree root I realized I had found something similar to Lepidodendron bark that I had just assumed was a piece of coral since I found it near other aquatic fossils. I found is somewhere near Decorah, Iowa (I don't remember exactly where). It's a bit worn, but does anyone know what it is? 

[gobbler716]

Lycopods, Lepidodendron, yes.

[gobbler716]

They are all over Alabama!

[minnbuckeye]

I hunt the Decorah area. It is mainly Ordovician. This likely rules out gobbler's suggestion. I feel this is a stream worn piece of a recepticulite. They are commonly found in the area.

[FossilDAWG]

While I can see a superficial resemblance to a lycopod, the last photo shows tube-like structures extending into the specimen.  Such structures are not at all characteristic of lycopods, and they strongly support the recepticulites ID offered by minnbuckeye.  Also the bedrock around Decorah, Iowa is marine Ordovician, far too old and the wrong environment for lycopod trees, and there is no terrestrial Carboniferous anywhere close to that area.

 

Don

[Micah]

Interesting! I thought the structure was all wrong for it to be treeish, but the resemblance got me wondering... First I've ever heard of recepticulites, they seem pretty interesting, especially since (at least in a very quick search) they aren't very well understood yet.

[abyssunder]

If there is an intersecting pattern of clockwise and counterclockwise rows of rhombus shaped plates or stalk spaces, then it is a receptaculitid, like Receptaculites.

[doushantuo]

Hinde:

[doushantuo]

Henry:

[doushantuo]

Funnily enough,both Lepidodendron and the receptaculids have this pattern of para-and orthostichies

especes-du-genre-lepidodendron.pdf

 

 

 

[FossilDAWG]

By the way the recepticulitids have been revised and the common Decorah form is now assigned to the genus Fisherites.  Older references called it Recepticulites, but that genus had to be divided due to significant differences between the type species of Recepticulites and those species now assigned to Fisherites.  I don't know that your specimen is well enough preserved to confidently assign it to a species.

 

Don

[minnbuckeye]

10 hours ago, Micah said:

Interesting! I thought the structure was all wrong for it to be treeish, but the resemblance got me wondering... First I've ever heard of recepticulites, they seem pretty interesting, especially since (at least in a very quick search) they aren't very well understood yet.

 

 

 If ever back in the Decorah area or SE Minnesota, let me know and I can put you onto complete specimens that hopefully are not as worn either. I have a mathematical mind and the geometric patterns on these have always impressed me! Reminds me of playing Spirograph as a child.

[Micah]

 

1 hour ago, minnbuckeye said:

Reminds me of playing Spirograph as a child.

I can definately see the resemblance now that you mention it!  Thanks for the offer I'll definately let you know if I'm in the area!

[doushantuo]

one of the best

finneyfisheritreceptaculiapp38-233.pdf

 

outtake: