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Devonian oddball


Kane

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During a hunt in the upper Widder Fm (Devonian) in the Thedford area, I encountered these curious bits among the usual clatter of trilobites, brachs, and nautiloids. 

 

I have some ideas, but would like to see if they are on - or off - the mark. I've largely ruled out worm burrows as they appear in these shales as generally very thin and pyritized. They look like some form of plant matter, which would be a first for me in these shales.

 

I've collected the positive and impression. It measures about 3 cm. They appear to have very fine, fibrous striations (although detail is wanting when using the iPad camera :P ). 

 

Could be something very underwhelming, but thought I'd canvass opinions! Thanks for having a look. :) 

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...How to Philosophize with a Hammer

 

 

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Plant's a possibility from the photos, although the environment is indeed odd. I can see it's very fibrous, but not much beyond that; given that, though. a sponge root tuft is another option. Pyrite replacement of the silica is very common in mudstones. Probably needs a very good close-up shot to be sure, I'm afraid!

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Thanks, @Spongy Joe! I had not even considered the possibility of a sponge root tuft, and that would still be a first for me in these muddy shales. The upper part of this formation has large intervals of quick burial, but also wave deposits (with only very thin intervals where trilobites come out intact as opposed to the product of being in a blender :D ). Of course, as you said, a closer image will be required to come to a definitive conclusion - something I plan to do once I get back from a few days out of town, and can hook up the microscope's camera. Glad I picked it up!

...How to Philosophize with a Hammer

 

 

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That's grand, Kane - hope the microscope does the trick! I guess we'll see in a few days... :)

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Perhaps not relevant, but in the Maryland members of the Mahantango formation, annelid worm burrows that look like this are common. 

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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Just now, WhodamanHD said:

Perhaps not relevant, but in the Maryland members of the Mahantango formation, annelid worm burrows that look like this are common. 

I agree. 

I know you said you've ruled them out, Kane, but that's what they look like to me. 

Another type and preservation of burrow 

Life's Good!

Tortoise Friend.

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5 hours ago, Tidgy's Dad said:

I agree. 

I know you said you've ruled them out, Kane, but that's what they look like to me. 

Another type and preservation of burrow 

Definitely something I can't absolutely rule out, for sure. Magnification will help to confirm either way. It would be a not so typical ichnofossil given the prevalence of much thinner, pyritized types. At this point, I'm not wedded to any possibility. :) Better to pick up the oddities than leave them in the field and never know! It wouldn't be my first temporary head-scratcher from that shale.

...How to Philosophize with a Hammer

 

 

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6 hours ago, WhodamanHD said:

...in the Maryland members of the Mahantango formation, annelid worm burrows that look like this are common.

Near the town of Capon Bridge, West Virginia, there are Silurian exposures of gray mudstone/shale that are just full of these finger-width 'flattened ropes'. Interestingly, they are all coated with some form of iron that really stands out against the soft gray matrix.

I hope the specimens in question are plant, which would be very cool!

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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The undulating fibrous structure is clearly visible on the external surface of the specimen, but I'm wondering if those "fibers" are only a surface feature (as ornament) or they are present also in the "body" ?

" 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

My Library

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3 minutes ago, abyssunder said:

The undulating fibrous structure is clearly visible on the external surface of the specimen, but I'm wondering if those "fibers" are only a surface feature (as ornament) or they are present also in the "body" ?

Until I can get home, I am not sure. :headscratch: I would be embarrassed for this to be a wild goose chase and turn out to be something very mundane. :(  At the least, if it is an ichnofossil, at least it is not a common one in this shale. I will take a few images of the interior, too. 

...How to Philosophize with a Hammer

 

 

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Break out the hi-res microscope, and give us a good look.

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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As promised, some microscope-enabled closeups. A view of the exterior looking down, and one from the cross-section that I converted to black and white to remove distracting colour details. The cross section seems to have "fibre bundles."

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...How to Philosophize with a Hammer

 

 

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the carbonaceous looking material gives the impression that this is plant. The way it's crushed also gives that impression.

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Thank you, @Plax!

 

If it is indeed plant material, this may be cause for some small excitement. The only reference I've found to plant material in the Widder was an off-topic reference to Tasmanites sp. in Murphy, J. (1972) "Echinocaris Punctata (Hall) from the Hamilton Group, Thedford, Ontario" The Ohio Journal of Science 72.3: 155-7. I don't seem to have a more recent reference on hand, and the classic (but somewhat dated) Stumm and Wright checklist does not report plants in this formation. :( 

...How to Philosophize with a Hammer

 

 

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Tasmanites are spores.  Stauffer 1915 reported these plants from nearby Kettle Point.  Protosalvinia is a synonym of Tasmanites.

 

Plantae
Knorria sp.
Lepidodendron primaevum 
Pseudobornia inornatus 

Protosalvinia huronensis

 

Stauffer, C.R. 1915

The Devonian of Southwestern Ontario.

Geological Survey of Canada Memoir, 34:1-341  PDF LINK

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Just now, piranha said:

Tasmanites are spores.  Stauffer 1915 reported these plants from nearby Kettle Point.  Protosalvinia is a synonym of Tasmanites.

 

Plantae
Knorria sp.
Lepidodendron primaevum 
Pseudobornia inornatus 

Protosalvinia huronensis

 

Stauffer, C.R. 1915

The Devonian of Southwestern Ontario.

Geological Survey of Canada Memoir, 34:1-341  PDF LINK

Thanks, Scott. I looked this up and saw entries for algae. Not sure why that article's author would call them plant matter. :headscratch:

 

Thanks for the link: I'm going to follow up on those species to see if I can match diagnostic details and better refine a possible ID. I still haven't entirely ruled out worm burrow, but the cross-section does seem to suggest plant matter as per my initial guess. 

 

Still, fairly uncommon in this formation (at least from all my time cracking it). 

...How to Philosophize with a Hammer

 

 

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35 minutes ago, Kane said:

...the cross-section does seem to suggest plant matter...

Your micro-photos show that these are not burrows, but have an organized structure. What then, if not plant?

Very cool!

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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Just now, Auspex said:

Your micro-photos show that these are not burrows, but have an organized structure. What then, if not plant?

Very cool!

Thanks, Chas! :) 

 

Plant materials is not all that common here. Must have been some drift action! I don't usually get excited about plant material, trilobitocentric as I am, but this is kind of cool! The shales have been kind...

...How to Philosophize with a Hammer

 

 

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With the new images I think burrow can be ruled out. It might be plant, or maybe a sponge

" 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

My Library

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