Belated DSR Report: Part II - Brachiopoda

[Peat Burns]

These were collected at DSR during the TFF hunt last year.  I am just getting around to processing the specimens.  It's amazing that the diversity of bivalves I acquired was greater than the brachiopods!  First, a picture of the site:

 

Now the brachiopods (scale in mm):

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Peat Burns]

Now, with this one, I struggled.  I rested on Orthospirifer cf. O. marcyi, although they are a bit smaller than average.  The unique character that I based this on was the radiating capillae in the fold and sulcus.  These seemed to also be present in the plications, but ever so faintly.  Here are pictures of the capillae in the fold and sulcus with "nodes" or "granules":

 

 

Here is a picture of Orthospirifer cooperi from the Silica Shale showing the capillae and nodes / granules for comparison:

 

 

Here are the shells of the cf. Orthospirifer marcyi (DSR) (scale in mm)

 

 

 

Any comments or suggestions on these are most welcome.  @Al Tahan do your "hybrid" Mediospirifer / Spinocyrtia have this feature?

 

@Jeffrey P, @Tidgy's Dad

 

 

[doushantuo]

very reasonable brach pix,Peat!

[Tidgy's Dad]

Lovely specimens! 

Oh, golly. 

The problematic species is about half the size of the usual Orthospirifer marcyi that I have seen, but I guess they'd have to have juveniles and little ones. 

I think this is probably a small individual as i can't locate other reasonable alternatives. 

But there probably are some. 

[Monica]

Those are gorgeous brachiopods!!!  Thanks for the eye candy! 

[Peat Burns]

11 hours ago, doushantuo said:

very reasonable brach pix,Peat!

Thanks, Ben 

11 hours ago, Tidgy's Dad said:

Lovely specimens! 

Oh, golly. 

The problematic species is about half the size of the usual Orthospirifer marcyi that I have seen, but I guess they'd have to have juveniles and little ones. 

I think this is probably a small individual as i can't locate other reasonable alternatives. 

But there probably are some. 

Thanks, Adam.  Yeah, I'm not terribly happy with the ID yet, either.  There's another genus/sp. I was considering (which I can't remember at the moment and my literature is not handy), but unfortunately none of the photos available online for these species (including photos from museum collections) have sufficient resolution to see the ultrastructure. And, unfortunately, I don't have any of either species for comparison.  Maybe I can find a confirmed O. marcyi for purchase.  I wasn't able to locate the original description (Spirifer marcyi). 

 

You bring up an interesting point.  There had to be some "juvenile mortality" in brachiopods.  But i rarely find them much smaller than the typical size range for the respective species (one of the reasons I'm still uneasy about my ID).  Perhaps they were fast-growing little buggers. 

7 hours ago, Monica said:

Those are gorgeous brachiopods!!!  Thanks for the eye candy! 

Thanks, Monica. Happy to reciprocate for all the Ordovician eye candy you post! 

[Fossildude19]

Very cool finds, Peat.   

[Peat Burns]

20 minutes ago, Fossildude19 said:

Very cool finds, Peat.   

Thanks, Tim .  It was a fun trip and a pleasure meeting you there.  Hopefully, I can get back there again someday.

[Fossildude19]

2 minutes ago, Peat Burns said:

Thanks, Tim .  It was a fun trip and a pleasure meeting you there.  Hopefully, I can get back there again someday.

Thanks Tony. It was really nice to meet you, as well. 

Hope to see you somewhere again.  

[Wrangellian]

I can't help with the ID problem, but great specimens, I especially like the lingulid, and the Longispina is interesting. Nice photography too - your photog skills/setup are a little better than mine

Will we be seeing the bivalves next? (I won't be able to help with any IDs there either but will be interested to see them).

[Peat Burns]

6 minutes ago, Wrangellian said:

I can't help with the ID problem, but great specimens, I especially like the lingulid, and the Longispina is interesting. Nice photography too - your photog skills/setup are a little better than mine

Will we be seeing the bivalves next? (I won't be able to help with any IDs there either but will be interested to see them).

Thanks Wrangellian . I use these cheap LED photography lights I get on Am*z*n. 

They're about $5 each.  They're nice because you can lay them at different angles to get the oblique lighting to show surface detail.  I just use my Samsung Galaxy S10 for the photos  (sometimes through the dissecting scope for smaller fossils).

 

The genus Longispina was a first for me.  I think you can see the spines at the hinge extremities.  I didn't prep any further for fear I'd break the few that were still intact.

 

The bivalves (in my opinion the best part of DSR ) are posted here:

 

[Wrangellian]

Ah, thanks.

Yes, I did notice those spines!

[Jeffrey P]

Hi Tony. Nice sample of DSR brachiopods there. I agree with most of your IDs, however I have doubts about the Cryptonella, but frankly I'm not sure what it is. Also, the Orthospirifer looks more like a Mucrospirifer to me. The last one, which is mostly an internal mold without the benefit of ornamentation, I'm thinking is more likely a Mediospirifer, but without sufficient diagnostic information may be impossible to fully nail down. Great photography and presentation. Congratulations. Is that me in the upper right hand corner? Can't tell though that's certainly my bucket and backpack. Great collecting with you.  

[Peat Burns]

Thanks Jeff, for your continued input and advice on these.  Regarding the photo of the site, I didn't want to publish anyone's photo publicly without permission (or at least not a photo big enough for facial recognition), so I just got that shot of your bucket and bag.  I was working the layer just below that, so you'll know where that new-for-the-site bivalve came from .  It was fun collecting with you and the others.  Definitely one of my favorite trips (right on par with digging dinosaurs out west - my heart is really in the palaeozoic...)

3 hours ago, Jeffrey P said:

I agree with most of your IDs, however I have doubts about the Cryptonella, but frankly I'm not sure what it is.

Yeah, that photo isn't very fair to post because 1) it is not magnified sufficiently to show the pores characteristic of Terebratulida, and 2) I neglected to mention the pores.  But it does have beautifully preserved pores on one solitary patch of remaining shell on the other side.  The rest of the fossil has tiny casts of the pores.  I think Wilson only listed three Middle Devonian Terebratulids, and Cryptonella seemed the most likely of the three (despite it being really too compressed and poorly preserved to be sure)

3 hours ago, Jeffrey P said:

the Orthospirifer looks more like a Mucrospirifer to me

I had these in with the Mucrospirifer box initially.  But then I started looking at the folds of Mucrospirifer and noted that they typically show marked growth lines and lack the radial capillae.  The ones I thought might be Orthospirifer also have a fairly high cardinal area as compared to the typical Mucrospirifer.  You could be right, though.  

 

 

 

[Tidgy's Dad]

On 6/17/2020 at 2:27 AM, Peat Burns said:

 

You bring up an interesting point.  There had to be some "juvenile mortality" in brachiopods.  But i rarely find them much smaller than the typical size range for the respective species (one of the reasons I'm still uneasy about my ID).  Perhaps they were fast-growing little buggers.

Yes, this I have read about, they attain an 'adult' size very quickly and then keep slowly growing through life. Modern brachiopods can attain adult (there is no 'full') size within weeks. 

So, a 'youngster' is probably the smallest one you have from any location ( different location and environments equals different size of mature individuals, sometimes). 

But young ones are sometimes found, I have a couple in my collection, but that's nothing compared to the total number of 'adults' I have. 

[FossilDAWG]

I did not know that about brachiopod growth rates!

However I assume maximum size (for a species) would be influenced by the environment?  Generally (but maybe not always) individuals tend to be larger in carbonate rocks that were deposited in warm clear (little suspended sediment) water, compared to shales often deposited in deeper, perhaps cooler water with a substantial influx of fine sediment.  At least that seems to be my experience.

 

Don

[Tidgy's Dad]

21 hours ago, FossilDAWG said:

I did not know that about brachiopod growth rates!

However I assume maximum size (for a species) would be influenced by the environment?  Generally (but maybe not always) individuals tend to be larger in carbonate rocks that were deposited in warm clear (little suspended sediment) water, compared to shales often deposited in deeper, perhaps cooler water with a substantial influx of fine sediment.  At least that seems to be my experience.

 

Don

Yes, environmental conditions are key. When I have my computer back again, I'll post some interesting papers on research of modern brachiopods in different locations around the Antarctic where depth, temperature, competition and substrate all effect the sizes of the populations within the same species.

I have noted that some fossil  species, Zygospira modesta being a good example, are noticably different sizes from locality to locality with each group all being more or less the same, presumably adult size, within each site but often substantially larger or smaller at other locations. 

[Peat Burns]

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