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Peat Burns

Unknown object / shell

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Peat Burns

Found this while sorting matrix for micros.  It's shaped like a brachiopod or bivalve shell, strongly concavo-convex.  It has widely-spaced spines and very fine growth lines that follow the margin of the shell.  I found two of them, and they are about 4 - 5 mm in diameter.  My best guess is that they are "larval" shells of the gastropod Spiniplatyceras rarispina that have had the protoconch break off.  I can't think of any brachiopods from that locality and time period that would have spines like that.  It reminds me of the Permian Echinaurus, lol.  Any thoughts? @Tidgy's Dad, @FossilDAWG

5e17d1acbb598_UnknownBell.thumb.png.4fe0b0b6b7ac73d830b03773bc1337a0.png

 

5e17d1b947368_UnknownBell2.thumb.png.71c18049c8dd5cfc4b8439b2c5b90201.png

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Tidgy's Dad

Interesting finds.:)

Did the larval Spiniplatyceras exhibit such spines?  

And I don't know Spinulocosta so can't comment further. 

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Peat Burns
2 hours ago, Shamalama said:

What formation and age does the material come from? My first thought is Spinulocosta spinulocosta which replaced Productella spinulocosta.

https://viewsofthemahantango.blogspot.com/2014/12/a-new-specimen-of-productella.html

Sorry, I put the formation and age in the tags and forgot to put it in the post.  This is middle Devonian Bell Shale of the Traverse Group 

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Peat Burns

Thanks to @Bobby Rico, I think I've found a possible match for this specimen - the productid brachiopod Devonalosia.  Not sure if it's been recorded in the Bell Shale before, but it occurs in the Arkona and Silica (so certainly a reasonable possibility).

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Shamalama

Looks very similar to Productella and Spinulocosta but is listed in a different family. I wonder what the differences are that separate Devonalosia from the other two?

 

image.png.5d7cd005f484839244cdc1539f4f4cd9.png

 

 

Seek and ye shall find... A description of Devonalosia wrightorium from "Morphology, Classification and Life Habits of the Productoidea (Brachiopoda)", 1960, Helen Marguerite Muir-Wood, Gustav Arthur Cooper

 

image.png.1ad2c2cdc5da1a99d30c9a8cc6f11cf1.png

 

So since Stumm and Wright ("Checklist of Fossil Invertebrate species... of Southwestern Ontario", 1958) list Productella truncata and P. spinulocosta as being found in the Arkona formation (and Hungry Hollow member of the Widder formation), I should probably change my labels to list my specimens as Devonalosia wrightorium.

 

You learn something new everyday!

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Peat Burns
4 hours ago, Shamalama said:

Looks very similar to Productella and Spinulocosta but is listed in a different family. I wonder what the differences are that separate Devonalosia from the other two?

Seek and ye shall find... A description of Devonalosia wrightorium from "Morphology, Classification and Life Habits of the Productoidea (Brachiopoda)", 1960, Helen Marguerite Muir-Wood, Gustav Arthur Cooper

So since Stumm and Wright ("Checklist of Fossil Invertebrate species... of Southwestern Ontario", 1958) list Productella truncata and P. spinulocosta as being found in the Arkona formation (and Hungry Hollow member of the Widder formation), I should probably change my labels to list my specimens as Devonalosia wrightorium.

You learn something new everyday!

Very cool! I'm glad to get this one figured out and glad that you can update yours.  Do you think yours look more comparable to Devonalosia?  The one that @Bobby Rico showed (see below) and the pictures online of Devonalosia looked like they had more widely-spaced spines, which more closely matches what I found.  Off to the primary literature...

 

3F0A88C1-9432-4A64-831A-032BFE617EF2.jpeg

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Shamalama

I can't argue about spine distances but that could be a somewhat variable feature and may not be the best guide to go with.

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