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Middle Devonian Bryozoan?


Kane

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Beyond being able to pick out a fenestellate bryozoan, my knowledge of bryozoans is quite poor. I was hoping for an ID on this one (bryozoan? sponge?), which is among the most peculiar I've found around these parts (these parts being fill deposited from Bois Blanc / Amherstburg Fms). Those large, circular pores were what persuaded me to take it home. Is it even a bryozoan? 

 

It is about an inch (though no saying how large it might have spread). 

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...How to Philosophize with a Hammer

 

 

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Interesting. It sort of looks like the remnants of an encrusting bryozoan that was attached to a substrate.

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This is based more on a gut feeling I get from modern beach combing, but the vibe I get is algae.

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Maybe a bryozoan similar to Sulcoretepora?

 

Sulcoretepora_sp_20170317.thumb.jpg.ac87888e776eb2518b4ca0f78adfa311.jpg

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

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Could be a Sulcoretepora sp...? The apertures are fairly large, but there is this strange concentric branching that is throwing me for a loop, otherwise it looks vaguely similar to Proavella sp. (but that one has a kind of "dimpling" rather than concentric radiating of branches, and the apertures are smaller) :headscratch:

 

Proavella sp. image from "Geoscience Collections of Estonia"

398-1031_1.jpg

...How to Philosophize with a Hammer

 

 

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It looks close also to Graptodictya (the sister taxa of Proavella, although I don't know if it was described from Bois Blanc / Amherstburg Fms.

 

di.thumb.jpg.0d3689a7549b34caa64aa1572077ccf0.jpg

picture from here

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

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or maybe Clathropora?

 

FullSizeRender.jpg.1d9162a299a6aa82517ce96d73609aaf.thumb.jpg.23d4fd048dfacc99627b4388e2dc6a5f.jpg593334baadf94_Clathroporabaltica.thumb.jpg.8162dc225551391b2fe631bb6aa4013f.jpg

picture from here

 

Try to find out which one was described in J. A. Fagerstrom. 1961. The fauna of the Middle Devonian Formosa Reef Limestone of southwestern Ontario. Journal of Paleontology 35(1):1-48

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

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Thanks, @abyssunder - I just acquired that article moments ago. Some of the plates are a bit tough to make out, but I'm checking now...

UPDATE: Closest match (but not close enough!) was Fistiulipora and a species of Syringopora. I might be able to rule out Amhertsburg Fm and will now see if I can get my mitts on some Bois Blanc descriptions.

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5 minutes ago, GeschWhat said:

That is beautiful, whatever it is!

Thanks! It was right next to a fenestellate one in the same rock - It was so odd, I couldn't resist taking it home :) 

...How to Philosophize with a Hammer

 

 

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But can anyone point to a spot called remnant in these examples that doesn't look 'zooidic' ? 

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1 hour ago, Kane said:

Thanks, @abyssunder - I just acquired that article moments ago. Some of the plates are a bit tough to make out, but I'm checking now...

UPDATE: Closest match (but not close enough!) was Fistiulipora and a species of Syringopora. I might be able to rule out Amhertsburg Fm and will now see if I can get my mitts on some Bois Blanc descriptions.

I think Syringopora coral is unlikely , I would rule out.
Don't looks like the cystoporid Fistulipora, to me. :headscratch:
The other one, Sulcoretepora, is mentioned in the document?

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

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10 hours ago, DPS Ammonite said:

Interesting. It sort of looks like the remnants of an encrusting bryozoan that was attached to a substrate.

I agree although I can't back it up. .looks like most of the bryozoa is gone and you are left with just the basal attachment layer..

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11 hours ago, DPS Ammonite said:

Interesting. It sort of looks like the remnants of an encrusting bryozoan that was attached to a substrate.

 

I agree too. There are a couple of small patches at the edges (left and top) showing zooecial apertures which might let a specialist identify it further. 

Colony form alone may not be enough, unless there's an identical one described from the same formation. (And, unless a specialist saw them, older references often lump bryozoans into catch-all genera, so it might have been called Sulcoretepora for example.)

Tarquin

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Thanks everyone!

@abyssunder - Yes, a Sulcoretepora sp. is described in Fagerstrom:

 

"This specimen is a short bifoliate stem with three rows of apertures on each flattened side and none on the edges. Slightly raised longitudinal ridges separate adjacent rows of apertures. Apparently no mesopores are present between apertures but they may have been destroyed by recrystallization" (17).

 

That being said, it could also be from Bois Blanc rocks, and I don't have a one-stop source for identifying all the fauna listed in them (more or less cobbled together from a variety of sources that are not specifically indexed on the formation). It is reported in the Delaware limestone, which is younger than Bois Blanc Fm (and younger than the Oriskany Fm). 

 

Those two patches are certainly not much to go on! But @DPS Ammonite and @TqB are probably right in pointing out that this is mostly remnant substrate. I may as well put this piece aside for now and dig a bit more - in the rock piles and in the literature! I would certainly bring it to a specialist, but there's not as much interest in invertebrate fossils up in these parts anymore :( 

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Hi @Kane - I think the structure with ridges and apertures that's being described there is similar to this (actually a Carboniferous Sulcoretepora parallela, from Bancroft's 1988 Ph. D. thesis on Carboniferous bryozoa which is freely available). ("Bifoliate" presumably means it has a branch?)

 

5934057581a53_ScreenShot2017-06-04at13_59_23.png.253b96f1ad9f1d3608f261b2296c94c0.png

 

  

Tarquin

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Those visible patches (mentioned by Tarquin) have made me think it's a bryozoan from the beginning, the other parts being strongly weathered. As I'm not a bryozoa specialist, I would tentatively label it as Sulcoretepora ? sp., (with the question mark).

" We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. "

Thomas Mann

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12 minutes ago, abyssunder said:

Those visible patches (mentioned by Tarquin) have made me think it's a bryozoan from the beginning, the other parts being strongly weathered. As I'm not a bryozoa specialist, I would tentatively label it as Sulcoretepora ? sp., (with the question mark).

That's how I decided to label it on my blog. There just isn't enough full diagnostic detail to be absolutely certain :(. That being said, there's still some chunks from the same rock I can go back and retrieve to see if - maybe - there is more to be found in it. As I did split to find this one, I should probably retrieve the impression which may have some further detail.

45 minutes ago, TqB said:

Hi @Kane - I think the structure with ridges and apertures that's being described there is similar to this (actually a Carboniferous Sulcoretepora parallela, from Bancroft's 1988 Ph. D. thesis on Carboniferous bryozoa which is freely available). ("Bifoliate" presumably means it has a branch?)

 

 

  

My thanks! The image in Bancroft's dissertation is very similar to the Sulcoretepora sp pictured in Fagerstrom (although the picture in Fagerstrom's plate is quite tiny and hard to make out!). 

 

And thanks again to everyone for helping out. :) I do like these longer threads where identification is a challenge. Apart from expanding my very limited knowledge on bryozoans, I've also had a lot of practice typing out Sulcoretepora :D 

 

I'll keep this thread going if I can find a bit more of this lacy critter!

...How to Philosophize with a Hammer

 

 

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owen(1969):
"Genus SULCORETEPORA D’Orbigny 1849
The original description was brief but clear: “cellules placed by lines in grooves on one side of small simple branches”. No attempt was made to describe the internal
characters and the cystose structure of the walls in the exozone was not then known. Flustra parallela Phillips was the first recorded species and is therefore the type
species. As this has apertures on both sides of branches, the above description should be amended."

 

"Material: LL2673 a and b from Hessilhead.
Description: Zoarium bifoliate, straplike, 1-13 mm in width and 0.5-0-7 mm thick, with apertures commonly in five rows on both sides, in hollows separated by
longitudinal ridges. The zoarial edges are angular and nontelluliferous.
Zooecia arise from a non-perforate central wall, and after lying nearly horizontal, curve sharply through a vestibule to the surface. The endozone is thin-walled and
short, the exozone cystose at first, the cystopores covered with granular tissue. No acanthopores or hemisepta. Apertures oval, ringed, 4 in 2 mm longitudinally, arranged
quincuncially, averaging 0.3 by 0.15 mm. Ridges straight and in these slightly worn specimens simple.
Remarks: These thin straplike Bryozoa are common and unmistakable."

 

 

mind you,this is parallela.

edit: non telluliferous?

 

 

 

 

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Bryozoans are hard to ID.  Even a hard genus-level identification without thin sections is difficult. For years I was confused by fenestrates that were preserved on the matrix but were face up on one and face down on the other. You also have to pay close attention to the scale of the illustrations or photo plates. Side by side they may appear similar until you understand one is 1X and the other 2.5X size.  I think this specimen may be "face down" and the zooids are mostly hidden except a few spots where they appear to be weathering thru.

 

I applaud you for picking up and keeping the weird one. Still surprised by collectors who leave behind things they can't ID in the field. Those are always my favorites.

 

Also, Hall did some very extensive work on the bryozoans of NY back in the 1800's. If you can get your hands on one with the original books with litho plates you may find your answer.

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