Input requested (UPDATE!)

[piranha]

1 hour ago, Peat Burns said:

Yes, I was surprised, too. I'm not seeing the apical bladders .  I thought Inocaulus and Buthotrephis looked like better matches (although the latter has micro "tubules" that don't appear present in mine).  But he's the expert.  I'll put his name on the label so he can take all credit or blame

 

 

After reading the entire paper, I discovered Taggart & Parker provides an explanation for the apparent discrepancy:

 

"A large number of specimens show partially collapsed bladders.  Although some of these may represent ontogenetic phases in development, the decayed nature of most such material suggests that the bladders may have collapsed from the fully inflated condition.  A combination of collapse and partial decay produces specimens with superficial resemblance to fucoid growth forms and were not more complete material available, such specimens might be classified in form genera such as Buthotrephis or Fucoides.  These genera, however, are usually more extensively branched than Thalassocystis, have generally wider axes, and show no structural detail in the expanded branch tips."

[Tidgy's Dad]

14 hours ago, Peat Burns said:

I am.  I feel a little childish getting so excited about such things, but I can't help it.  I work regularly with living marine macroalgae from South Florida and have shelves of them in spirits, but I never imagined that I'd be holding one from the *middle Silurian* 

What a splendid result! 

This is most marvelous, and a really pretty specimen too.

I am also quite filled with covetousness. 

Congratulations! 

[Peat Burns]

9 hours ago, Tidgy's Dad said:

What a splendid result! 

This is most marvelous, and a really pretty specimen too.

I am also quite filled with covetousness. 

Congratulations! 

Thanks, TD.

[Pagurus]

It's hard to imagine the seaweed on my fishing line being preserved for 430 million years or so. In dolomite, no less. Wonderful.

[Peat Burns]

1 hour ago, Pagurus said:

It's hard to imagine the seaweed on my fishing line being preserved for 430 million years or so. In dolomite, no less. Wonderful.

It sounds like you speak from experience. Dasya and Sargassum are the worst. Someday someone will find a fossil of those with my fishing line still tangled in it.  Future TFF members will be arguing about the identity of the entwined object.  "It's A filamentous alga". 

 

"No, it can't be. I don't see any cross-walls". 

 

"Some filamentous algae are coenocytic and don't have cross-walls.  I'm in the Bryopsis camp." 

 

"It can't be Bryopsis... that's pinnately branched... this thing is not branched but I may be missing something because I'm using my smart watch..."

 

[Pagurus]

4 minutes ago, Peat Burns said:

Future TFF members will be arguing about the identity of the entwined object. "It's A filamentous alga". ......

 

[EMP]

On 4/18/2018 at 4:53 PM, Peat Burns said:

Thank you! I'm ecstatic about this.  It's the first non-calcareous palaeozoic alga in the collection.  I need to get U.P. there and look for more!

 

Hahaha, something only a true fossil collector would say. 

 

Nice find!

[fifbrindacier]

Great find Peat, congratulations.

[Peat Burns]

11 minutes ago, EMP said:

 

Hahaha, something only a true fossil collector would say. 

 

Nice find!

 

1 minute ago, fifbrindacier said:

Great find Peat, congratulations.

Thank you! 

[Peat Burns]

Today, I cut out the fossil alga from the sizable rock in which it was preserved.  Here it is.

 

 

[Peat Burns]

I dissected the rest of the rock which was a very fine crystalline dolomite with faint somewhat poorly defined bedding planes.  I thought the dark inclusions might be more algae, but they turned out to be pyrite.

 

 

I did manage to find this.  At first glance, it is reminiscent of a burrow, but I don't think it is.  Among other things it would be inconsistent with the palaeoenvironment / environment of deposition.  On the other hand, it is not carbonized like the Thalassocystis compression.

 

Not sure what it is.  Maybe an alga or maybe a soft-bodied colonial invertebrate.

[doushantuo]

that last one is a bit of a spine-tingler

A list of known fossil occurences of incertae sedis/algal(thalloid)/coelenterate/hemichordate morphological interface fossils

 

 

 

[Tidgy's Dad]

That really is a beautiful specimen. 

The preserved detail is exquisite! 

A  very special find indeed! 

[Spongy Joe]

Gorgeous alga. That second find is also very intriguing... from the scale alone, my hunch is burrow or perhaps partly-decayed alga. Does the thing cross bedding planes? (It looks like it does, pointing towards alga.) And could you wet it and then take a very-close-up image of anything that might be a structure within it? (the upper part seems to have distinct walls and possibly transverse structures.)

 

I wouldn't rule out organic worm tubes of some sort, but it may just be too far gone to be sure; sometimes, the only thing left to say is, "Find me a better one!"

[Pemphix]

Congrats !

Very rare and cool find !

 

[Peat Burns]

On 5/4/2018 at 8:15 AM, Pemphix said:

Congrats !

Very rare and cool find !

 

Thanks 

[Peat Burns]

On 5/4/2018 at 6:54 AM, Spongy Joe said:

could you wet it and then take a very-close-up image

Here are some images of the fossil wet.  Microscopic observation shows no details.  However, wetting the fossil and playing with the brightness, contrast, and greyscale does appear to reveal light and dark bands. I plan to take a trip up there this summer and do some intensive sampling 

 

[Peat Burns]

[abyssunder]

They look  like worms, to me, of course not as old like the Early Cambrian Cricocosmiids. They look segmented.

[Spongy Joe]

Interesting...

 

I'm pretty certain it's not worms, since they seem to be branching off each other, and the banding is too irregular, but organic tubes belonging to 'worms' is a definite possibility. Something like pogonophorans might do it, or perhaps cephalodiscid hemichordates (my wife says they're bigger than rhabdopleurans, which only get to a mm or so wide and have a more regular branching pattern).

 

Getting more specimens is a good plan! In the meantime, is there any thickness to the discoloured area of the 'tubes'?

[abyssunder]

I'm not convinced that there is a branching character, it might be a superposed intersection between the truncated elements, but I could be wrong.

[Spongy Joe]

You might be right, Abyssunder - it's hard to be sure without having the slab in your hands! (Can you tell if it's branching, Peat?)

 

It just doesn't look right for worm soft tissue, to me, though. Aside from the irregular transverse banding, I've seen a fair few worms over the years, and this preservation just doesn't quite do it. One of those deeply scientific hunches, you know...

[Peat Burns]

5 hours ago, Spongy Joe said:

Interesting...

 

I'm pretty certain it's not worms, since they seem to be branching off each other, and the banding is too irregular, but organic tubes belonging to 'worms' is a definite possibility. Something like pogonophorans might do it, or perhaps cephalodiscid hemichordates (my wife says they're bigger than rhabdopleurans, which only get to a mm or so wide and have a more regular branching pattern).

 

Getting more specimens is a good plan! In the meantime, is there any thickness to the discoloured area of the 'tubes'?

Thanks for the help.  Here is a picture of a fracture that cuts through some of the "thalli". As you can see, there is no evidence of much thickness.

 

 

The red lines outline where the branches are on the surface.  The more I look at it under the scope and compare with the specimen of Thalassocystis, the more I think it is an alga that has lost the carbonized film.  The texture of the compression matches, anyway.