Unknown Mississippian Marine Fossil UTAH

[Thalo]

Fossil found in marine limestone deposit Ut. About 9” long. Formation from Mississippian according to USFS.

[hemipristis]

that is interesting!  My first guess is some type of crinoid

[Rockwood]

The fact that there is a similar shape under it combined with irregularities in it's symmetry makes me suspect it is a lens of darker material.

[westcoast]

I'm thinking inorganic on this. Weird concrection maybe..

[TqB]

Welcome to the forum by the way! That's wonderfully weird - I'm thinking concretion too, sort of septarian, with the ring-section bits being overgrowths from some of the septa.

[Thalo]

Not a lens - it has a very clear form. The  dark piece below is another fossil it is just too deformed to recognize any features. There are many other fossils near by in the same rock. This one is unusual because it is very large and the other fossils are tiny shapes of crinoid & bryozoan bits. I have looked at many fossils from this time period and nothing else like it. It is an animal or ocean plant if some kind. The form is too unusual to be a random rock formation. See how the bulb part has an even inner layer and those lobes down the stem portion are spaced evenly yet are not exactly the same? 

[Rockwood]

4 hours ago, Thalo said:

It is an animal or ocean plant if some kind.

In that case please let us know when you figure out what it is. We have been assuming that concretions can form in the same sediments as fossils.

[grandpa]

8 hours ago, Thalo said:

Not a lens - it has a very clear form

First, let me offer my welcome to TFF from Austin, Tx.

 

I tend to be in agreement with your above statement.  It looks too symmetrical to me to outright reject it as being inorganic in origin.  (Not sure that sentence is clear.  What I mean is I give it a fair to good chance that it is a critter of some kind.)  I sure don't know what I'm looking at, but I wonder if it is not a vertical cross-section of a "what-ever-it-is".  At any rate, I would not myself be willing to rule it out at this point.  Whatever it is, it has a very intriguing, aesthetic shape and should be held on to until a definitive answer can be obtained.  By definitive, I mean given a good "hands-on" look by someone who doesn't have to rely on pictures to make a determination.

9 hours ago, Thalo said:

The form is too unusual to be a random rock formation. See how . . . those lobes down the stem portion are spaced evenly yet are not exactly the same? 

We are in agreement.  The "segments" of the "tail" are also compelling.  But, I sure don't know what Mississippian creature it could be.  Maybe it is geologic, but it sure has compelling symmetry and a suggestive shape.  How long is it from tip to tip?

[Rockwood]

11 hours ago, Thalo said:

See how the bulb part has an even inner layer and those lobes down the stem portion are spaced evenly yet are not exactly the same? 

Statements of fact aside. You do have a good argument for the opinion.

Crinoid holdfast perhaps ? They can have a mix of symmetry and chaos.  

[Rockwood]

"Ready fire aim" again wasn't it  @grandpa ?

[grandpa]

5 minutes ago, Rockwood said:

"Ready fire aim" again wasn't it  @grandpa ?

Don't be too hard on yourself.  I'd label this one as "too soon to call".

[Rockwood]

[Mark Kmiecik]

7 hours ago, Rockwood said:

Yup. I'm grabbin' a comfy chair and a bowl of popcorn too. I've stared at it up, down and several times sideways and it keeps flipping from organic to geologic and back.

[Thalo]

It is a cross section. It is symmetric so, I am not seeing how it isn’t symmetric. Of course the symmetry is not perfect but that is even more like organic life.  It seems to have very clear compartments that seem structural. The outer loops must have gone around the whole stem like tubes or hoops. That bumpy structure of the outer layer also continues up over the bulb portion but much less pronounced there they are just a slight bumpy texture.  — I will go take more photos. The size It about 9” long but I will get the exact size. The bulb portion was hollow and has some quartz in there that is not any where else in the rock. I know it is weird. That is why its bugging me. It is not at all like the other fossils in this rock formation. —- I think is some kind of water plant. There is just no way though that it is a random rock formation it is just too much like life to not be. The form makes sense for  a water plant, with a structural supports and inner opened compartments. 

[Rockwood]

6 hours ago, Thalo said:

Of course the symmetry is not perfect but that is even more like organic life.

In this case nearly the same symmetry can also be seen in the rock itself though. 

Concretion commonly has a rind surrounding it as well.

I respect your opinion, but do not think there is sufficient evidence to say it is a life form.

[Rockwood]

On 8/28/2019 at 11:56 PM, Thalo said:

The  dark piece below is another fossil it is just too deformed to recognize any features.

Often the key to solving a puzzle like this is to find a specimen that has some more recognizable features linked to the less well preserved form. A transitional preservation if you will. 

[Scylla]

How about an ichnofossil, burrow infill with fecal pellets? That doesn't explain the "lobes" though.

[FossilNerd]

14 hours ago, Mark Kmiecik said:

Yup. I'm grabbin' a comfy chair and a bowl of popcorn too. I've stared at it up, down and several times sideways and it keeps flipping from organic to geologic and back.

Agreed. I’ve looked at this thing over and over. Scoured the internet and perused my documentation. I can’t find a good match, and I can’t make up my mind whether it is biological or geological. 

 

Right now I'm leaning more towards geological. The top “bulb” part looks like a concretion to me, but the lower “stem” part is throwing me for a loop. It could be some type of wild concretion as @westcoast and @TqB suggest. We all know Mother Nature can cook up some crazy things!   

[DeepTimeIsotopes]

What was the nearest town to where you found this? If we know that, we can find out if other similar specimens occurred nearby.