Hello.Is this a horned coral fossil?

[Tnmountains]

Hey. I posted this in the wrong spot and was recommended to you guys and gals. I found this on the Tennessee river on a Dallas site with artifacts. i thought it was a fossil from inside a snail. Saw it might be something called horned corral.I have not seen anything like this in our rivers before. So here are my pictures. Thanks for any help.
TnMountains

 

[fossil_femme]

not a horn coral, as it is hollow and there are no septa... maybe fossil sponge?
let's see what the experts say...

 

[Tnmountains]

Hey maybe its someting new....... nahhhh these fossil guys will know.Thanks for your help and direction fossil_femme.

 

[Harry Pristis]

Definitely not a "horn coral" (= solitary rugose coral), as 'fossil femme' has explained. It appears to be a remarkable bit of engineering. It looks to be an ichnofossil.

My guess is that this is the bottom of a burrow, lined by the invertebrate builder with tiny bits of debris and slime -- something like tiny spit-balls. But, that's just a guess based on seeing fossilized shrimp burrows.

 

[Mosasaurfiend]

I agree with them . I think that is a cliona sponge on it's surface too. Here is what
it looks like. Compare it to yours and see what you think. The round stuff at the top.

 

[Tnmountains]

So is it a sponge,,,, or a trace fossil showing the engineering of something the true fossil built? So the base was thicker just due to engineering? This hobby seems to be pretty interesting. I would like to post another large fossil I took a picture of for you guys if you have time.
So sponge or ichnofossil ? Im not sure Mosasaurfiend.

 

[Mosasaurfiend]

It can be both...IMHO

 

[Harry Pristis]

So is it a sponge,,,, or a trace fossil showing the engineering of something the true fossil built? So the base was thicker just due to engineering? This hobby seems to be pretty interesting. I would like to post another large fossil I took a picture of for you guys if you have time.
So sponge or ichnofossil ? Im not sure Mosasaurfiend.

'Mosasaurfiend' may have been referring to the tiny brown projections on the top exterior of the 'cup' in your second image. Those are the only things that have any resemblance to the sponges in the 'fiend's image.

It is certainly possible to have a fossil on an ichnofossil, though I am only confident of the ichnofossil in this case.

 

[Tnmountains]

Well then I am honored to have found a fiendish ichnofossil . I am pretty sure that I will have to write this down. They must be pretty common. Thanks for all the info.

TnMountains

 

[Eager Beaver]

Coral and shellfish make up 95% of the fossil record, so they are the most abundant.

 

[allen]

that is really an awesome find !