Devonian Brachiopods

[GreatHoatzin]

I found lots of these guys while searching in the Hungry Hollow formation near Arkona. Age is Middle/Upper Devonian.

[grandpa]

Beauties!

[Scylla]

Mucrospirifer

 

https://storymaps.arcgis.com/stories/b8a6c86f52744b8c854d8ff9ebd63b99

Edited September 25, 2022 by Scylla
Added link and corrected spelling

[GreatHoatzin]

57 minutes ago, Scylla said:

Mucrospirifer

Thanks! After doing a bit of research I’m pretty sure these are Mucrospirifer Thedfordensis now.

[fifbrindacier]

@Tidgy's Dad

[Tidgy's Dad]

On 9/25/2022 at 6:49 PM, Scylla said:

Mucrospirifer

 

https://storymaps.arcgis.com/stories/b8a6c86f52744b8c854d8ff9ebd63b99

The link is full of horrible inaccuracies, I'm afraid. 

I like this one : 

Mucrospirifer.pdf

All the ones seen above would seem to be M. mucronatus to me, except the one in the last photo that I'm not sure about. 

[GreatHoatzin]

1 hour ago, Tidgy's Dad said:

I like this one : 

Mucrospirifer.pdf 76 kB · 9 downloads

I am interested in looking into it. Would it be possible to provide this as something other than a .php file?

[Misha]

1 hour ago, Tidgy's Dad said:

The link is full of horrible inaccuracies, I'm afraid. 

I like this one : 

Mucrospirifer.pdf 76 kB · 11 downloads

All the ones seen above would seem to be M. mucronatus to me, except the one in the last photo that I'm not sure about. 

Are they not Mucrospirifer arkonensis, at least the second to last ones?

Edited September 28, 2022 by Misha

[Tidgy's Dad]

1 hour ago, GreatHoatzin said:

I am interested in looking into it. Would it be possible to provide this as something other than a .php file?

 

Not sure why it's done that. 

 

Edited September 28, 2022 by Tidgy's Dad

[Tidgy's Dad]

1 hour ago, Misha said:

Are they not Mucrospirifer arkonensis, at least the second to last ones?

Nope. 

Mucrospirifer arkonensis is now M. mucronatus again. It was originally M. mucronatus, but then Shimer and Grabau, 1902 classed it as M. mucrontus var. arkonensis and in the 50's became its own species, but was placed back as M. mucronatus by Tillman in 1964. 

[Ludwigia]

11 hours ago, Tidgy's Dad said:

Nope. 

Mucrospirifer arkonensis is now M. mucronatus again. It was originally M. mucronatus, but then Shimer and Grabau, 1902 classed it as M. mucrontus var. arkonensis and in the 50's became its own species, but was placed back as M. mucronatus by Tillman in 1964. 

 

I still get confused with these things. Couldn't this just as easily be a Mucrospirifer thedfordensis (Shimer & Grabau), or are we getting into synonyms now?

[Tidgy's Dad]

2 hours ago, Ludwigia said:

 

I still get confused with these things. Couldn't this just as easily be a Mucrospirifer thedfordensis (Shimer & Grabau), or are we getting into synonyms now?

Mucrospirifer thedfordensis is still valid. Mucrospirifer had over the years been split into a dozen or so different species and Tillman decided that most of these were synonyms of M. mucronatus, M. thedfordensis and M. norwoodensis (Michigan only along with the Petoskey stones). This only applies to the North American Middle Devonian forms. 

M. thedfordensis has a more V-shaped sulcus, than which can be U-shaped on occasion, it never has a flattened floor to the sulcus and has a low, quite convex fold which again isn't flattened. 

M. mucronatus has a more U-shaped sulcus with a flattened floor and subangular edges, and a more gently convex fold with a flattened top. 

[Ludwigia]

45 minutes ago, Tidgy's Dad said:

Mucrospirifer thedfordensis is still valid. Mucrospirifer had over the years been split into a dozen or so different species and Tillman decided that most of these were synonyms of M. mucronatus, M. thedfordensis and M. norwoodensis (Michigan only along with the Petoskey stones). This only applies to the North American Middle Devonian forms. 

M. thedfordensis has a more V-shaped sulcus, than which can be U-shaped on occasion, it never has a flattened floor to the sulcus and has a low, quite convex fold which again isn't flattened. 

M. mucronatus has a more U-shaped sulcus with a flattened floor and subangular edges, and a more gently convex fold with a flattened top. 

 

Thanks for the detailed explanation, Adam. Now I can finally get around to sorting out my Hungry Hollow finds.

[Tidgy's Dad]

1 hour ago, Ludwigia said:

 

Thanks for the detailed explanation, Adam. Now I can finally get around to sorting out my Hungry Hollow finds.

Yes, I'm looking forward to going through mine sometime in the next year. 

I believe that at Hungry Hollow the Arkona Shale contains M. mucronatus and the Widder Formation has M. thedfordensis. Not sure about the Hungry Hollow Formation. 

[Ludwigia]

10 minutes ago, Tidgy's Dad said:

Yes, I'm looking forward to going through mine sometime in the next year. 

I believe that at Hungry Hollow the Arkona Shale contains M. mucronatus and the Widder Formation has M. thedfordensis. Not sure about the Hungry Hollow Formation. 

Yes, that makes sense to me.

[Kane]

11 minutes ago, Tidgy's Dad said:

Yes, I'm looking forward to going through mine sometime in the next year. 

I believe that at Hungry Hollow the Arkona Shale contains M. mucronatus and the Widder Formation has M. thedfordensis. Not sure about the Hungry Hollow Formation. 

You should be "safe" in terms of the latter given that Hungry Hollow was demoted to member status of the Widder Fm. That is still a bone of contention, however. 

[Scylla]

On 9/28/2022 at 4:36 PM, Tidgy's Dad said:

The link is full of horrible inaccuracies, I'm afraid. 

I like this one : 

Mucrospirifer.pdf 76 kB · 19 downloads

All the ones seen above would seem to be M. mucronatus to me, except the one in the last photo that I'm not sure about. 

Thanks