Looking for plant ID

[M Harvey]

This is carbonized plant material from the Selma Chalk formation, central Alabama.  It is not uncommon to find terrestrial "driftwood"  but this is the first time I have found what appears to be a fruiting body.

There is a vertical center with radiating structures.  Reminds me superficially of a proteaceae

but I have no background on the subject. Any paleobotanists  out there?

 

 

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[Rockwood]

I'm not a paleobotanist, but thought it worth a bump to see if it might catch the attention of one.

My thought is perhaps it has the structure of a cycad.

[M Harvey]

Thanks for that.  Cycad was my first guess but I thought the leaves were wrong.  Now I think you are correct.  The size is right.  I thought this would be of interest because of the limited amount of  terrestrial Cretaceous material from the Eastern Appalachia side of the interior seaway.  Any fossils found could display some interesting evolutionary divergences.  

[TNCollector]

I have not collected the Selma Chalk, but I do often collect the Demopolis Chalk, which is not that far away from the Selma both geographically and geologically.

 

I do not think this is plant material. Most of the plant material that I find is carbonized, and it is highly unlikely that any 3D paleobotanicals in the Selma chalk would not be petrified wood. The Selma is a seafloor deposit, and most plant material is simply sunken driftwood. Your specimen does not appear to be carbonized, rather it looks iron-based. 

 

This specimen does however look very similar to the many ghost shrimp burrows that can be found in the Mississippi Embayment Cretaceous deposits. The ones I find in the Demopolis appear to be made of the same iron-based concretion material that mine are. The dense core of the burrow is where the hollow burrow was filled with sand, and the strange looking striated texture on the outside is where the shrimp filled the walls of the sand with mucous to keep the walls in place.

 

[Rockwood]

4 hours ago, TNCollector said:

I have not collected the Selma Chalk, but I do often collect the Demopolis Chalk, which is not that far away from the Selma both geographically and geologically.

 

I do not think this is plant material. Most of the plant material that I find is carbonized, and it is highly unlikely that any 3D paleobotanicals in the Selma chalk would not be petrified wood. The Selma is a seafloor deposit, and most plant material is simply sunken driftwood. Your specimen does not appear to be carbonized, rather it looks iron-based. 

 

This specimen does however look very similar to the many ghost shrimp burrows that can be found in the Mississippi Embayment Cretaceous deposits. The ones I find in the Demopolis appear to be made of the same iron-based concretion material that mine are. The dense core of the burrow is where the hollow burrow was filled with sand, and the strange looking striated texture on the outside is where the shrimp filled the walls of the sand with mucous to keep the walls in place.

 

Didn't see that coming.

I agree it's a bit light on carbonized look, but it seems to completely lack the dobbed look that I've come to expect in ghost shrimp burrows.

I have no experience with chalk formations, but have seen lignite to some degree molded and replaced by iron oxide. Chalk would seem porous enough to facilitate the process quite well.