Mississippian unknown

[Peat Burns]

Any ideas on the identity of this?

 

(Sorry, this was a field photo, so no scale)

 

Mississippian: Osagean - Elsey Fm. 

Silex, MO 

 

[Rockwood]

Bivalve, is the easiest thing for me to imagine it being. It's really just a guess though.

[Echinoid]

+1 for bivalve

[TqB]

I'm thinking brachiopod, something like but not quite Echinoconchus.

 

One of mine from UK Mississippian.

 

[Fossildude19]

Brachiopod for me too.  

That was my first impression.

[Peat Burns]

18 hours ago, Rockwood said:

Bivalve, is the easiest thing for me to imagine it being. It's really just a guess though.

 

18 hours ago, Echinoid said:

+1 for bivalve

 

15 hours ago, TqB said:

I'm thinking brachiopod, something like but not quite Echinoconchus.

 

One of mine from UK Mississippian.

 

 

 

13 hours ago, Fossildude19 said:

Brachiopod for me too.  

That was my first impression.

 

Thanks all .  I'm back from the field now and was able to get it under the scope.  Here are a couple of photos showing the nature of the pattern that perhaps wasn't visible in the field photo.  I am thinking this is a section through something rather than an exterior or an imprint.  Echinoderm?

 

Scale is in mm.

 

[Innocentx]

It may be a very worn spiney productid brachiopod. The v-shapes in your photo above, might be where spines were anchored.

[Peat Burns]

2 hours ago, Innocentx said:

It may be a very worn spiney productid brachiopod. The v-shapes in your photo above, might be where spines were anchored.

The complex structure of the "pores" is interesting.  It appears from the literature that brachiopod spines are hollow.  What are the "V" shaped structures? Anybody have a close-up pic of broken spines of a productid?

 

[TqB]

4 hours ago, Peat Burns said:

The complex structure of the "pores" is interesting.  It appears from the literature that brachiopod spines are hollow.  What are the "V" shaped structures? Anybody have a close-up pic of broken spines of a productid?

 

 

Here are a few (Echinoconchus again).

 

[Peat Burns]

1 hour ago, TqB said:

Here are a few (Echinoconchus again).

 

Thank you.  They do have a similar diamond shape.  The round holes in the middle are more what I would expect from broken spines. 

 

It seems like the most reasonable guess for now.  It's in chert, so prepping more out may be a problem. 

[Innocentx]

@Peat Burns. I am also a brachiopod enthusiast (upper Carboniferous, Kansas). I've looked through all my stuff and cannot find this(v-shaped) feature anywhere among the brachs, regardless of their state of wear. I've also gone through the usual echinoid suspects.

Maybe should get more eyes on this but not sure who to ask. @Missourian ?

[doushantuo]

Thinking a chonetid.

[Missourian]

Brachiopod has my vote.

 

I think the shell could be an external mold, with the truncated spines extending into the matrix, something like this (red surface):

 

[doushantuo]

Antiquatonia,i'm somehow thinking

[piranha]

This paper synonymized 'Grand Falls' with 'Elsey'. 

 

Robertson, C.E. 1967

The Elsey Formation and its relationship to the Grand Falls Chert.

Missouri Geological Survey and Water Resources, Reptort of Investigations, 38:1-62   PDF LINK

 

brachiopods:

 

Chonetes sp.

Chonetes illinoisensis?
Orthotetes keokuk

Delthyris similis
Tetracamera subtrigona

Pseudosyrinx sp.

Pseudosyrinx keokuk?
Torynifera pseudolineata

 

               

        Torynifer pseudolineatus  (Treatise H)                                  ???

 

 

This paper synonymized 'Elsey' with 'Reeds Spring'

 

Mazzullo, S.J., Wilhite, B.W., & Boardman, D.R. 2011

Lithostratigraphic Architecture of the Mississippian Reeds Spring Formation (Middle Osagean) in Southwest Missouri, Northwest Arkansas, and Northeast Oklahoma: Outcrop Analog of Subsurface Petroleum Reservoirs.  The Journal of the Oklahoma Geological Society, The Shale Shaker, 61(5):254-269

 

"The Elsey Formation was named by Robertson (1967) from exposures in the town of Reeds Spring west of Branson in Stone County, Missouri.  The outcrop there is now quite poor, and contacts with bounding formations are not exposed.  Nonetheless, based on our field studies we contend that the Elsey Formation is inconsistently applied, and its identification is fraught with much confusion.  Hence, we do not recognize this formation in the field area or in the subsurface to the west, and therefore, we recommend its abandonment as a formal stratigraphic entity."

[Innocentx]

If one were to abrade the ridges flat, it could reveal these v-shapes.

[westcoast]

7 hours ago, Innocentx said:

@Peat Burns. I am also a brachiopod enthusiast (upper Carboniferous, Kansas). I've looked through all my stuff and cannot find this(v-shaped) feature anywhere among the brachs, regardless of their state of wear. I've also gone through the usual echinoid suspects.

Maybe should get more eyes on this but not sure who to ask. @Missourian ?

Yes. It just doesn't look like brachiopod. Those odd features do not look like spines or spine bases .  They are too small and regular and while they appear to be very well preserved there is no obvious preservation of other shell layers. It's hard to see in the (excellent) photos but do those little leaf-like scars have depth into the body of the fossil or are they just on one surface layer. In the first image there appears to be some variation...

[Innocentx]

I don't like the idea that this fossil might go unidentified. I've seen this happen on the forum before. I understand that persons with greatest knowledge probably lose interest in looking at the ID section. Maybe there could be a special case section for things that are obviously fossils and yet no one who is participating can ID them to a satisfactory extent. Maybe it would attract more experts, who might see it as more challenging.

If there were such a section I would advocate for this fossil to be in it.

[Missourian]

9 minutes ago, Innocentx said:

I don't like the idea that this fossil might go unidentified. I've seen this happen on the forum before. I understand that persons with greatest knowledge probably lose interest in looking at the ID section. Maybe there could be a special case section for things that are obviously fossils and yet no one who is participating can ID them to a satisfactory extent. Maybe it would attract more experts, who might see it as more challenging.

If there were such a section I would advocate for this fossil to be in it.

 

I second this idea. If something languishes in the regular 'Fossil ID', it could be moved to the special section. Once the fossil is identified, it could then be moved back to the regular area. Perhaps it could be called 'Fossil ID Cold Cases'.

[Innocentx]

1 minute ago, Missourian said:

'Fossil ID Cold Cases'.

YES! Cool name.

[Peat Burns]

23 hours ago, westcoast said:

Yes. It just doesn't look like brachiopod. Those odd features do not look like spines or spine bases .  

I tend to agree, but I'm keeping an open mind.  Brachiopod never entered my mind from the time I found it, but my experience with productids is limited.

14 minutes ago, Innocentx said:

I don't like the idea that this fossil might go unidentified.

 

Although I don't have high hopes for revealing much with an air scribe in CHERT(!), I'm going to try it anyway.  I did have some success exposing a fenestrate bryozoan in the same stuff.  There does appear to be a "rind" or shell at the top of the fossil that might be revealing if exposed.  I won't let it die, but it might be a while before I can post an update, as I have about 500 lbs of new fossils to process. 

1 minute ago, Missourian said:

 

I second this idea. If something languishes in the regular 'Fossil ID', it could be moved to the special section. Once the fossil is identified, it could then be moved back to the regular area. Perhaps it could be called 'Fossil ID Cold Cases'.

Sounds like a good idea.  It could be fun!

[Innocentx]

6 minutes ago, Peat Burns said:

500 lbs of new fossils to process

holy moley

 

 

[Missourian]

5 minutes ago, Innocentx said:

holy moley

 

Heh. 500 lbs is an average day of hunting.

[Peat Burns]

2 minutes ago, Innocentx said:

holy moley

 

 

Lol.  I know... I just got back from a 4-state trip ending in New Mexico and including 6 geological time periods.  Some will go to museum.  Others will be used to trade on behalf of the museum.

 

[Innocentx]

@Peat Burns. So it's your job. Impressive and I'm jealous, but just a little bit. Sounds like a large task. I expect you're quite fulfilled by your work.