Tubular Bryozoan?

[KimTexan]

I had posted this piece in General Fossil Discussion area since it had my first trilobite on it. Someone message me saying that they thought it may be an echinoderm.

The person said “that looks like an echinoderm ("calcichordate")fragment.

Possibly the M1-M4 of a stylophoran(marginale elements)”

I thought it was a form of bryozoan. However, I do not know the Mississippian or any Carboniferous fossils very well. So I’m willing to admit complete ignorance.

 Can anyone ID it and educate me as what it is? 

 

I found it in Siloam Springs, Arkansas in an area which Mancos identified as the Pitkin Limestone, which is Mississippian. ROCKD ID’d the area as St. Joe’s limestone.

 

This is the item in question. I can’t say that I have seen segmented Bryozoa. The segments aren’t uniform in size.

Although, I’m not sure if the segments are endemic or an artifact of being broken. I believe they are breaks.

It is about 1.25 inches long and 7 mm wide.

 

Just a slightly zoomed in pic of the same thing.

A pic of the end.

 

This is is a pic of the back side of the other side of the plate and other end of it, where there is a cross section honeycomb looking view.

 

Your thoughts and comments would would be greatly appreciated.

 

Kim

[GeschWhat]

[KimTexan]

Hum, no thoughts?

Maybe one of you may have an idea. @doushantuo @Herb, @Pachy @Peat Burns @TqB

[ynot]

Looks bryozoan to Me. But I do not know echinoids very well.

[KimTexan]

54 minutes ago, ynot said:

Looks bryozoan to Me. But I do not know echinoids very well.

I know urchins well and crinoids a little. The rest I don’t know, but I’ve never seen any so porous.

Ive been trying to find Bryozoa, but I haven’t found one like this yet. There are 2-3, maybe more other types of Bryozoa on the plate.

[Bullsnake]

I would consider Fistulipora.

 

[Peat Burns]

I say bryozoan.  I won't even try to go further than that.  You might be able to narrow it down based on macroscopic characteristics if you had a species list for that site.  Otherwise it's acetate peels and microscopy in all likelihood.

[KimTexan]

 

 

22 minutes ago, Peat Burns said:

I say bryozoan.  I won't even try to go further than that.  You might be able to narrow it down based on macroscopic characteristics if you had a species list for that site.  Otherwise it's acetate peels and microscopy in all likelihood.

I have a microscope I bought when I was doing my clinical training. It’s pretty nice, but nothing I could easily look at fossils with unless they were small enough to fit under the objectives. I need to see if I can convert it to a dissecting type scope.

 

[KimTexan]

I am wondering if it could be something like 

Rhombopora.

[Peat Burns]

13 minutes ago, KimTexan said:

 

 

I have a microscope I bought when I was doing my clinical training. It’s pretty nice, but nothing I could easily look at fossils with unless they were small enough to fit under the objectives. I need to see if I can convert it to a dissecting type scope.

 

How to make an acetate peel

 

With an acetate peel, you may be able to use a microscope on low power (50x) since the acetates are transparent and sandwiched between microscope slides.

[TqB]

I've got very similar bryozoans from the UK Carboniferous put down as Tabulipora and the genus occurs in the USA. But as @Peat Burns says, you're likely to need microscopic detail of sections (and a specialist) for positive ID on these.

[Herb]

looks like a coral to me , Kim

[KimTexan]

12 hours ago, Herb said:

looks like a coral to me , Kim

Hum, what features indicate to you that it is coral? I’m trying to educate myself by asking such questions.

I haven’t found that kind of coral there before. There is horn coral in the area and lots of Bryozoa of various kinds.

[piranha]

list of Pitkin Bryozoa from:

 

Easton, W.H. 1943

The fauna of the Pitkin Formation of Arkansas.

Journal of Paleontology, 17(2):125-154

 

Anisotrypa solida Ulrich
Archimedes sp.
Archimedes communis (Ulrich)
Archimedes distans (Ulrich)
Archimedes intermedia (Ulrich)
Archimedes invaginata (Ulrich)
Archimedes proutana (Ulrich)

Archimedes swallovana (Hall)
Batostomella sp. 
Chilotrypa regularis n. sp.
Dichotrypa levis n. sp.
Dyscritella? sp. 
Fenestella [Fenestrellina] sp.
Fistulipora introspinosa n. sp.
Glyptopora michelinia (Prout) 
Glyptopora crassa n. sp.
Lyropora solida n. sp. 
Meekopora abrupta n. sp. 
Meekopora tenuis n. sp.
Polypora sp.
Polypora cf. P. whitei Ulrich
Rhombopora sp. 
Septopora cf. S. biserialis Swallow
Septopora cestriensis Prout
Septopora subquadrans Ulrich
Tabulipora cestriensis (Ulrich)
Tabulipora microfistulata n. sp. 
Tabulipora poculoformis n. sp.
Tabulipora reflexa n. sp. 
Tabulipora subtilis n. sp.

[KimTexan]

Ah, Rhombophora is in the list, but I have no idea what any of the others look like.

 

Someone who knows the area a little said the Pitkin was higher up. I was going off of what Mancos told me since I haven’t learned my formations there yet.

I tend to agree though. The Pitkin outcrops I’ve been to are higher up and full of crinoids. There is Pitkin a few miles away.

I tend to think this is more like the Boone formation closer to the St. Joe though, which is at the bottom of the Boone and lower Mississippian.

But the list is helpful, because I have bryozo from the Pitkin.

[TqB]

6 hours ago, KimTexan said:

Hum, what features indicate to you that it is coral? I’m trying to educate myself by asking such questions.

I haven’t found that kind of coral there before. There is horn coral in the area and lots of Bryozoa of various kinds.

The pores are too small for a coral. There is some overlap but these are well below the diameter you'd get in, say, a favositid. Otherwise, they can look very similar!

 

It isn't Rhombopora - the apertures in that are arranged in a regular pattern. I still think Tabulipora is a good possibility.

[Scylla]

On 7/26/2018 at 10:47 PM, KimTexan said:

 

 

I have a microscope I bought when I was doing my clinical training. It’s pretty nice, but nothing I could easily look at fossils with unless they were small enough to fit under the objectives. I need to see if I can convert it to a dissecting type scope.

 

The best way to convert a regular microscope to a dissecting scope is to sell it and use the cash to buy a used dissecting scope. I really think the segmentation of your bryzoan represents fracture lines.

[piranha]

7 hours ago, TqB said:

...I still think Tabulipora is a good possibility.

 

 

Gautier, T.G. 1970

Interpretive morphology and taxonomy of bryozoan genus Tabulipora.

University of Kansas Paleontological Contributions, 48:1-21  PDF LINK