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Mediospirifer

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I love finding multiple fossils. I don't just mean multiple specimens in a single rock, I mean fossils that show evidence of more than one life-form. Shells with burrow traces, for one example. Dung beetle balls. Predation marks. And particularly, epibionts.

 

Here I have a fairly ordinary specimen of the brachiopod Tropidoleptus carinatus. Ordinary, that is, until a closer look is taken....

 

DSCN7556.thumb.JPG.4db3a845aef15d884f26b7f56dc20283.JPGDSCN7576.thumb.JPG.9a73adf2ea01826283f6c7a8b4d33880.JPG

 

This specimen supported an variety of other critters on its pedicle valve. Whether the epibionts took hold while the brachiopod was alive, or colonized the dead shell, I don't know; I would speculate the former, as the brachiopod is articulated. I think it is likely that the whole living community was buried together by mud.

 

So who's here? Let's take a closer look.

 

We have several examples of Cornulites hamiltoniae. Some are (relatively) large, while others are very small:

 

5a0f5f35f30ce_Cornulites1.thumb.jpg.fc4b64bc4674eb359fb8b7141af3b389.jpg5a0f5f5629654_Cornulites2.thumb.jpg.4c9afa562b05720a80111422052a4f63.jpg

 

5a0f5fb7025f6_Cornulites3.thumb.jpg.91fafa267742b3f41695865aef42b7a3.jpg5a0f5fe480541_Cornulites4.thumb.jpg.2f218e942509631587cd4670e664ee50.jpg

 

Two more Cornulites pictures, then we'll see who else lived here! :D

 

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Here are the other Cornulites:

 

5a0f61946f42e_Cornulites5.thumb.jpg.a66bd7f018e1f266a2a08ab1e5890e1a.jpg5a0f619606b2f_Cornulites6.thumb.jpg.83f3713300ae7428ecf0d6464ea4cb32.jpg

 

Cornulites are thought to be tubeworms, although they're still under Incerta sedis in the fossil guides. Here's a different species of (suspected but not certain) tubeworm that lived on this shell, Palaeoconchus angulatus:

 

Palaeoconchus.thumb.jpg.4bdcdc3437cc28ad04aacb60b3d7fba5.jpg

 

There are also at least four crinoids that lived here. Species unknown, but at least two, possibly three or four different ones:

 

5a0f619773ab2_Crinoid1.thumb.jpg.34046728a11db9fff8b38bce339529d0.jpg5a0f6198de24f_Crinoid2.thumb.jpg.59210142ab2fbe459f40558eff02e496.jpg

5a0f619a6b607_Crinoid3.thumb.jpg.0efc96f4030f6f8d1c1e1599496cf7ae.jpg5a0f619c00675_Crinoid4.thumb.jpg.5d200ebfd7510235dbca305a88f179e9.jpg

 

And one last photo, of what, I'm not sure. Anyone recognize this?

 

5a0f619f18dfe_Unidentified1.thumb.jpg.1a682a690696e549460850a9ab4dea99.jpg

 

It might be the bud of a Hederella colony, or another Cornulites or Palaeoconchus. Or it might not! :D

 

This specimen was found as surface float. Middle Devonian, Livingston Cty, NY, Kashong member of the Moscow Fm., Hamilton Gp.

 

 

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3 minutes ago, Tidgy's Dad said:

Fascinating. I love this sort of thing too. 

Bryozoans next ?

 

Other than Hederella, I haven't found much in the way of encrusting bryozoans at this exposure. This specimen didn't have any well-established Hederella colonies, although some others I've found there do. Granted, I've only visited this site once, so I may well have missed a lot!

 

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2 minutes ago, Mediospirifer said:

 

Other than Hederella, I haven't found much in the way of encrusting bryozoans at this exposure. This specimen didn't have any well-established Hederella colonies, although some others I've found there do. Granted, I've only visited this site once, so I may well have missed a lot!

 

I saw the little stars and thought they may be crinoid holdfasts but went for the bryozoan option instead. 

Oh, well. :)

Thanks for posting, they're lovely.

Life's Good!

Tortoise Friend.

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4 minutes ago, Mediospirifer said:

 

Other than Hederella, I haven't found much in the way of encrusting bryozoans at this exposure. This specimen didn't have any well-established Hederella colonies, although some others I've found there do. Granted, I've only visited this site once, so I may well have missed a lot!

 

 

Let me amend that. I do have some crinoid stem sections and small gastropods (Naticonema lineata) that have bryozoan crusts, but I haven't identified them yet. Hederella is far more common among the pieces I've collected.

 

3 minutes ago, Tidgy's Dad said:

I saw the little stars and thought they may be crinoid holdfasts but went for the bryozoan option instead. 

Oh, well. :)

Thanks for posting, they're lovely.

 

I agree! :D Thanks for sharing your thoughts.

 

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The cornulites is an excellent find.  I learned recently that they are simply encrusting colonial tentaculites.  Awesome.  

----------------------------------------------------------------------------------------------------------------------------

Arizona Chris

Paleo Web Site:  http://schursastrophotography.com/fossiladventures.html

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A few more photos that I overlooked earlier. How did I miss them? Well, the ones I posted are photo-stacked (my first successful stackings!), and got renamed when I saved the composite images. These four were single photos, so they didn't get renamed...

 

Two more Cornulites:

 

Image17383.thumb.jpg.2004a5f1b7608839a505d690d17c2a2c.jpgImage17396.thumb.jpg.c49f31d1a68194ef6795195e06de2e47.jpg

 

And two more unidentified. The first may be another crinoid holdfast:

 

Image17533.thumb.jpg.a112a47c2c3550f72b0d8d1fd877e1a9.jpgImage17543.thumb.jpg.7ac79ec0e21be67d2b35ef27ce76cc8f.jpg

 

Thanks to all for the comments!

 

 

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  • 2 years later...
On 18.11.2017 at 1:21 AM, Mediospirifer said:

Whether the epibionts took hold while the brachiopod was alive, or colonized the dead shell

Epizoans have attached on the dead shells, because Cornulites sp. (Cornulitida) grow in different directions (Note the orientation of cornulitids towards the anterior commissure). Feeding advantage (see more Vinn O., Adaptive strategies in the evolution of encrusting tentaculitoid tubeworms, 2010): These organisms have benefited from feeding currents generated by the host (Brachiopoda). But, in this case they have benefited from water current only. We can see a lot of epizoans on the pedicle valve, because the brachial valve have been on the mud (dead brachiopod have laid on the sea-floor sediments). And it's laid in steady (stable) position (it has been transfered by current and turned). 

5e19b017df805_.JPG.2f7f328fb8451fa7692dd721eea0d2f3.JPG5e19b343b9fa7_.JPG.9590682bf314e88088c59aef897be09a.JPG5e19bc163684b_.JPG.377b223adfd5ac54add1f7dc047bb576.JPG

 

On 18.11.2017 at 1:21 AM, Mediospirifer said:

the whole living community was buried together by mud.

Yes, and many many times, because this is interbedded mudstone (coquina/coquina bed)

 5e19bd42a5526_.JPG.73d6ba4528483890165123f49f927e30.JPG

 

On 18.11.2017 at 1:36 AM, Mediospirifer said:

Here's a different species of (suspected but not certain) tubeworm that lived on this shell, Palaeoconchus angulatus:

it looks like Microconchida. I am not sure that Palaeoconchus sp. but Microconchida :)

I don't know, do you have Microconchus sp. in N.Y.?

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On 18.11.2017 at 1:36 AM, Mediospirifer said:

There are also at least four crinoids that lived here.

:blink: 4 in 1... it's very rare fossil on the brachiopods in Russia... How often do you find them on the brachiopods in N.Y. (Are "Crinoid holdfast" common fossils?) 

 

On 18.11.2017 at 1:36 AM, Mediospirifer said:

And one last photo, of what, I'm not sure. Anyone recognize this?

5e19cb9380627_.JPG.958323b614ebc859da8b800806c0264b.JPG

Sometimes Cornulites sp. grows around Palaeoconchus sp. :) 

May be it's the same specimen (fossil)?

148801482467415-big.thumb.jpg.84a9a41e472c369ae97318165b12562b.jpg

 

 

Edited by Brach3
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