Brachiopod Derbyia crassa from Pennsylvania Finis Shale fm, Lost Creek Reservoir near Jacksboro, Texas

[gwestbrook]

Found this somewhat flattened Brach (Derbyia crassa) in the Pennsylvanian age Finis Shale formation at the Lost Creek Reservoir borrow pit near Jacksboro, in Jack County, Texas a couple of weeks ago. It's not perfect but I love fossils that are still in the matrix and that aren't pristine and show signs of predation and deformation from the weight of the overlying matrix. 

[Ludwigia]

Then you certainly got what you were looking for. Good size too!

[gwestbrook]

2 hours ago, Ludwigia said:

Then you certainly got what you were looking for. Good size too!

Thanks! 

[Tidgy's Dad]

Very nice brachiopod. 

I'm very fond of brachiopods. 

[izak_]

I love brachs, nice find!

[Peat Burns]

[BobWill]

That's a real beauty Gary. Those are so thin and fragile it's rare to find them intact in the shale. Yours being in the limestone is probably all that's holding it together. Ludwigia is right about the size too. That's usually what I go by to tell Derbia crassa from D.Jacksboroensis so I'm wondering what's a better way to tell them apart. Both are on the list for Lost Creek spillway and I have what I think are some of each from there but I read where the latter which are larger are more common there in the Cisco Group and the former common in the Canyon Group of the Bridgeport and Brownwood areas. This according to Mark McKinzie but he left out any other details for telling them apart.

[Fossildude19]

Very cool brachiopod. 

Some fossils tell stories, ... and some more than others. 

This one looks like it might have an epic yarn to spin.

Thanks for showing us. 

Regards,

[gwestbrook]

9 hours ago, Tidgy's Dad said:

Very nice brachiopod. 

I'm very fond of brachiopods. 

Thanks! 

[gwestbrook]

2 hours ago, Fossildude19 said:

Very cool brachiopod. 

Some fossils tell stories, ... and some more than others. 

This one looks like it might have an epic yarn to spin.

Thanks for showing us. 

Regards,

Thanks! That's what I like most about those types of fossils. 

 

[gwestbrook]

3 hours ago, BobWill said:

That's a real beauty Gary. Those are so thin and fragile it's rare to find them intact in the shale. Yours being in the limestone is probably all that's holding it together. Ludwigia is right about the size too. That's usually what I go by to tell Derbia crassa from D.Jacksboroensis so I'm wondering what's a better way to tell them apart. Both are on the list for Lost Creek spillway and I have what I think are some of each from there but I read where the latter which are larger are more common there in the Cisco Group and the former common in the Canyon Group of the Bridgeport and Brownwood areas. This according to Mark McKinzie but he left out any other details for telling them apart.

Thanks, Bob! I just compared it to the photos I could find of the two. It looked closest to the crassa species, so that's the one I picked. I know I could be wrong though. Yes, the shell is very thin for sure. I could tell as I was cleaning around it. There are some edge pieces missing. The deposits that are still on it are very hard and I figured if I tried to remove them mechanically or chemically it might damage it even more, so I left what's there for that reason. 

 

5 hours ago, Peat Burns said:

Thanks! Best one I've found at that site.  I know others have found better though. But, I like it a lot. 

 

[gwestbrook]

3 hours ago, BobWill said:

That's a real beauty Gary. Those are so thin and fragile it's rare to find them intact in the shale. Yours being in the limestone is probably all that's holding it together. Ludwigia is right about the size too. That's usually what I go by to tell Derbia crassa from D.Jacksboroensis so I'm wondering what's a better way to tell them apart. Both are on the list for Lost Creek spillway and I have what I think are some of each from there but I read where the latter which are larger are more common there in the Cisco Group and the former common in the Canyon Group of the Bridgeport and Brownwood areas. This according to Mark McKinzie but he left out any other details for telling them apart.

Thanks for the information and the help with it, Bob! Much appreciated. 

 

[MeargleSchmeargl]

Looks like it's made of chocolate! Mmm, now I want a Hershey's. 

 

Neat brach! I also have a soft spot for them (though not as pronounced as my trilo spot). 

[Heteromorph]

Nice brachiopod! It must have quite an interesting story. 

[gwestbrook]

19 hours ago, Heteromorph said:

Nice brachiopod! It must have quite an interesting story. 

Yes, sir! I bet you it does too. 

[gwestbrook]

Just now, EchieMysticTx61 said:

Yes, sir! I bet you it does too. 

Thank you! I do love trilos too! Just so darn far from any good sources and I have a limited travel budget.  Wish I could hunt for those more. 

 

[Monica]

Beautiful find! 

 

(I like fossils left in matrix, too - they make for great display pieces!)

[ynot]

Nice fossil!

[stats]

Very nice... Derbyia is one of my favorite brachiopods.  They are fairly common in the Permian of Kansas.  They are always flat.  Here's a couple pictures of the ones I have found.

 

Cheers,

Rich

 

 

[gwestbrook]

14 hours ago, stats said:

Very nice... Derbyia is one of my favorite brachiopods.  They are fairly common in the Permian of Kansas.  They are always flat.  Here's a couple pictures of the ones I have found.

 

Cheers,

Rich

 

 

Awesome! Very nice! Thanks for sharing. 

[gwestbrook]

On 3/29/2018 at 10:07 PM, ynot said:

Nice fossil!

Thank you! 

 

[gwestbrook]

On 3/29/2018 at 5:12 PM, Monica said:

Beautiful find! 

 

(I like fossils left in matrix, too - they make for great display pieces!)

Thanks!