Rugose or Bryozoan?

[REW01]

Is this a rugose coral or a bryozoan? There are definite bryozoans in this rock of different types. I was thinking it's a rugose coral, but want other eyes on this specimen.

 

Collected from the Phosphoria Formation in Wyoming, so it's Permian in age.

[Rockwood]

I think I would go bryozoan. I'm not at at all sure though.

[TqB]

I think bryozoan too. The radiating structure looks like packed zooecial tubes, not septa.

[REW01]

That’s the thing, I’m not sure. I wasn’t seeing clear septa but it also doesn’t look quite like zooecia in comparison to bryozoa I’ve got from this same site. I’ve also never seen a bryo with a central opening like this. Hence my trouble IDing it. 

[Rockwood]

23 minutes ago, REW01 said:

I’ve also never seen a bryo with a central opening like this. Hence my trouble IDing it. 

A big part of my reluctance to commit. Maybe just an object (fossil?) that the ancestrula happened to find itself on ?

[grandpa]

35 minutes ago, REW01 said:

I’ve also never seen a bryo with a central opening like this.

That is also what is holding me back from offering an ID.  It looks like a rugose at very first glance, but then there is that structure in the center of the specimen - and the cellular structure of the radial arms doesn't seem right. 

What is that thing in the center about? 

Doesn't look convincingly like a bryo or a coral to me from the perspective of that separate structure in the center. 

Could you give us a close-up of the surface texture of that center feature so that we can get a better sense of what it might be?  Also a closer look at the radial structure might help too.

[REW01]

10 minutes ago, grandpa said:

That is also what is holding me back from offering an ID.  It looks like a rugose at very first glance, but then there is that structure in the center of the specimen - and the cellular structure of the radial arms doesn't seem right. 

What is that thing in the center about? 

Doesn't look convincingly like a bryo or a coral to me from the perspective of that separate structure in the center. 

Could you give us a close-up of the surface texture of that center feature so that we can get a better sense of what it might be?  Also a closer look at the radial structure might help too.

Is this close up sufficient? I only have my phone camera at the moment so can’t take truly good macro photos. 

[Rockwood]

I think the feature is a culmination of various diagenetic events, including recrystallization and weathering.

[grandpa]

Well, I'm not sure.  The close-up quality is fine, but I'm still not sure what I'm looking at.  I don't see any structure that shouts "organic" or "cell structure".  It looks more like radial calcite crystalization around a calcitic center.  If it is of organic source, I'm afraid the source of origin may be erased by the crystalization.  Too bad we can't see a "side view" of the object.  But that might not help either.  Sorry I can't be more definitive.

 

I see that @Rockwood was responding as I was writing the above.  I think he and I are saying similar things; he's just much more succinct.

[Rockwood]

4 minutes ago, grandpa said:

I think he and I are saying similar things; he's just much more succinct.

I'm afraid my succinct might suck.

I was referring to the center while arguing that it is a bryozoan.

[grandpa]

2 minutes ago, Rockwood said:

I was referring to the center while arguing that it is a bryozoan.

Ooh!    Never mind. 

 

On a more serious note, when you look at the close-up of the radial structure, what features do you see that leads you to conclude bryo?  I must be missing something.

[Rockwood]

15 minutes ago, grandpa said:

Ooh!    Never mind. 

 

On a more serious note, when you look at the close-up of the radial structure, what features do you see that leads you to conclude bryo?  I must be missing something.

I think I can make out the tiny radiating tubes that one would expect in a bryozoan in a few different areas. There are a lot of tiny dark circles for it to be strictly crystal.

[grandpa]

@Rockwood you may be right.  I'm having a hard time seeing tubes with enough certainty to say definitely, but I can imagine what you are seeing.  I'd like to see the specimen under a scope to get a better sense of the crystal/tube structure before totally agreeing, but your judgement is likely correct.  If you think you can see tubes with certainty, then I'll trust your eyes and judgement.

[REW01]

It seems the consensus is that it's probably bryozoan. I was leaning that way, so you guys have been helpful. 

 

It is pretty weathered, which definitely doesn't lend itself to an easy ID. Glad I'm not the only one to get a little hung up on what this thing is.