Spines on silicified Latiproductus, Mississippian, England.

[TqB]

Probably Latiproductus latissimus, Great Limestone, Mississippian, Pendleian Stage, Co. Durham, England.

 

I've dissolved out a few silicified partial shells of this common large productid  but these are the first attached spines I've come across so far. I can't find any literature where these have been figured before for this genus. Four are showing; there may well be more but the piece is very fragile and I'm stopping here! 
They only occur on the ventral (pedicle) valve, judging by the spine bases.

The second photo is of a more complete ventral shell in the same piece, with typical spine bases.

 

Scale in mm

 

 

 

Usual preservation after acid extraction in this bed. (55mm across, quite small for the species.)

Edited April 30 by TqB

[Kato]

Nice! What are you using as a dissolving agent? The spines I find seem to be generally associated to but not attached, though there could be spines hidden in the matrix still attached to the soecimen.

[Tidgy's Dad]

Wow!

Beautiful.

[Doctor Mud]

Wow! Incredible that they are preserved and incredible that you managed to prep them out! They look so delicate. 
 

lucky that they are silicified. Imagine prepping these! 

[TqB]

12 hours ago, Kato said:

Nice! What are you using as a dissolving agent? The spines I find seem to be generally associated to but not attached, though there could be spines hidden in the matrix still attached to the soecimen.

Thanks! Mostly hydrochloric acid, about 5% (just diluted builders' brick cleaner). I switched to 10% acetic on this one as the spines appeared though I don't think it made much difference apart from being slower.  
Detached spines are the commonest fossil in this limestone.

[TqB]

9 hours ago, Tidgy's Dad said:

Wow!

Beautiful.

Thanks, Adam. I hope there will be more - I have a few more blocks to dissolve.

 

[TqB]

6 hours ago, Doctor Mud said:

Wow! Incredible that they are preserved and incredible that you managed to prep them out! They look so delicate. 
 

lucky that they are silicified. Imagine prepping these! 

Thanks! I think they'd be impossible without acid as the limestone is very hard. I don't think air abrasion would work very well though I haven't tried it.

[Yoda]

@TqB

That's really nice. 

And well prepped 

[TqB]

3 hours ago, Yoda said:

@TqB

That's really nice. 

And well prepped 

Thank you! It's all down to the acid really.