Are these fossil Fish Rakers or mandible material in fish vomit? (Missouri)

[Samurai]

Location: Missouri

Age: Pennsylvanian

Lithology: Muncie Creek Shale 

 

 

Hello! I am starting to officially dive into fish anatomy to better understand the nodules I had collected from several years ago. I saw this structure in one of my fish regurgitates and I was wondering if these were in line with gill rakers or some sort of piece from a mandible that got broken up a lot. I don't think it's teeth as they look too thin and rod-like, along with being spread apart. 

 

If these are indeed gill rakers I hear that these are good for species identification and classification but I do not know if that rings true on fossilized fish. If that is the case I may need to email the people I sent my braincase to 5 years ago. Let me know what you guys think! 

 

 

I always called these fish prey species A because their scales end up being present in a lot of fish regurgitation. 

 

 

 

 

Edited May 22 by Samurai

[Mark Kmiecik]

It looks like a variation of a geologic crystallization phenomenon known as boxwork. Google images of boxwoork and compare.

 

P.S. -- Size can vary from millimeters to meters.

 

 

 

Edited May 22 by Mark Kmiecik
add postscript

[Samurai]

8 minutes ago, Mark Kmiecik said:

It looks like a variation of a geologic crystallization phenomenon known as boxwork. Google images of boxwoork and compare.

 

P.S. -- Size can vary from millimeters to meters.

 

 

 

Odd, normally these nodules are so tightly packed water can't intrude, hence the preservation of cartilage in some of these. Do they normally look this uniform since they are microscopic? I guess it's possible as weirder things have been preserved in these phosphate nodules. Its nestled in between fish bone/scales so I was not sure.

 

Here is a side view of the same piece with slight bending

 

It is only occurring on that side of the nodule and nowhere else. 

 

also, are these hollow?

 

[ynot]

Does not match any box work I have seen. 

I think gill rakers is a good ID..

But I am not well versed in fish anatomy..

[Mark Kmiecik]

Took another look at these and I agree they could be gill rakers. I always thought that gill rakers were more uniform in length and spacing, but after a couple of minutes of online research I find I was wrong. I see a few in the enlarged photos that seem to be hollow. Is that possible?

[Samurai]

50 minutes ago, Mark Kmiecik said:

Took another look at these and I agree they could be gill rakers. I always thought that gill rakers were more uniform in length and spacing, but after a couple of minutes of online research I find I was wrong. I see a few in the enlarged photos that seem to be hollow. Is that possible?

Your guess is as good as mine  sometimes crystallization/replacement can coat things leaving behind a void in the middle but I am not too well versed in fish anatomy myself as I have so far only seen larger easier to identified bones and structures such as the operculum/series, gular bones, ribs, Ptergiophores. I might have to find some modern fish skeletons to study. 

 

 

Edit: @Mark Kmiecik I have seen similar preservation occur in brachiopods and preserve the brachium around the lophophores although this would be too big and its calcite replacement, not phosphate. Its just a similar case.

 

 

 

Ultimately I am at a loss. Maybe I'll send an email to some of the fish people I've talked to in the past and see what they think. 

Edited May 22 by Samurai

[Fossildude19]

I wonder if this isn't some sort of internal mold of a bryozoan.   Not seeing fish material here.

[Samurai]

25 minutes ago, Fossildude19 said:

I wonder if this isn't some sort of internal mold of a bryozoan.   Not seeing fish material here.

Oops, that's my fault for not showing a scale:

Sadly I no longer have access to a microscope and only a handheld lens. How small can the branches on microscopic bryozoans be?

 

the fish scales are on the top left in blue:

Edited May 22 by Samurai

[Fossildude19]

2 hours ago, Samurai said:

Oops, that's my fault for not showing a scale:

 

Sadly I no longer have access to a microscope and only a handheld lens. How small can the branches on microscopic bryozoans be?

 

 

I was thinking that it was some sort of internal cast, so the "Branches" would actually be the zooecia. 

 

With the better photos, (thanks) I agree, it is probably something fish related, but, not sure what.  

[Jaybot]

Just a side note, interesting how different Muncie creek shale concretions can look.

Where I collect mine, they are nearly black on the outside, and dark grey on the inside.

I have found at a different locality ones that look more like yours.  Curious, out of 100, how many

would you say have something interesting in them (in your experience @Samurai)?

For me it's about 5-8 out of 100 concretions.

 

It tests my patience

[Samurai]

1 hour ago, Jaybot said:

Just a side note, interesting how different Muncie creek shale concretions can look.

Where I collect mine, they are nearly black on the outside, and dark grey on the inside.

I have found at a different locality ones that look more like yours.  Curious, out of 100, how many

would you say have something interesting in them (in your experience @Samurai)?

For me it's about 5-8 out of 100 concretions.

 

It tests my patience

Alot of my old ones come from an abandoned rock pile from a few years ago, some even came from the paola and raytown limestone that I hammered out, hence why they can look a little dirty/yellow on the outside. Most are already weathered out for a few years.

 

Recently I learned land ownership changed and its been a challenge to get into contact with the new owners so I've since stopped hunting there and instead have been hunting at and looking for other Muncie locations/new black shales. I still have a couple bags full from when I first hunted there that I haven't cracked yet.

 

I assume yours are coming straight out of the shale itself? 

 

As for interesting materials I would say about in about 100 fair sized nodules I would find maybe 1 or 3 Very good finds like fish vomit, mandibles, interesting cartilage shapes that can include jaws, recognizable bone, good coprolites, then about 5 being misc amorphous cartilage pieces or sparce scales (mostly from this poor prey species above) and some scales from possibly Lawrenciella, but that is still in the works. The rest are usually phosphate duds but some contain weird cherty-like forms come out of the nodules as well which I never really found out what it was. Shell iridescence sort of fits in this category. Im still dreaming for a full shrimp like the ones Missourian had found. Ive found only tails so far.

 

For ultra rare finds I would rate complete shrimp/ammonite/braincase at the top. ive found only 3 braincases and 1 partial before my first Ammonite in the nodules. 1/1000+ for braincase and id say 1/3000+ for Shrimp/ammonite almost. Although that is including small nodules. 

 

I would say the best nodules are Irregularly long/oval in shape. Size isn't always a factor but bigger the better.  Sometimes the nodules will have visible parts sticking out on the surface. I once found a Campodus sp. tooth sticking on the outside of a nodules surface, which I found humorous. I ended up giving it to a friend I was hunting with at the time before I took a picture. 

Edited May 23 by Samurai

[Jaybot]

2 minutes ago, Samurai said:

I assume yours are coming straight out of the shale itself? 

Yes

3 minutes ago, Samurai said:

As for interesting materials I would say about in about 100 fair sized nodules I would find maybe 1 or 3 Very good finds like fish vomit, mandibles, interesting cartilage shapes that can include jaws, recognizable bone, good coprolites, then about 5 being misc amorphous cartilage pieces or sparce scales (mostly from this poor prey species above) and some scales from possibly Lawrenciella, but that is still in the works. The rest are usually phosphate duds but some contain weird cherty-like forms come out of the nodules as well which I never really found out what it was. Shell iridescence sort of fits in this category.

Sounds like we experience the same odds then

3 minutes ago, Samurai said:

Im still dreaming for a full shrimp like the ones Missoruian had found.

Me too 

 

I haven’t been cracking these concretions for as long as you have, so a Campodus tooth is my personal best.  Neat that you found a few brain cases and one ammonite!  Gives me some hope

 

 

[Samurai]

1 minute ago, Jaybot said:

Yes

Sounds like we experience the same odds then

Me too 

 

I haven’t been cracking these concretions for as long as you have, so a Campodus tooth is my personal best.  Neat that you found a few brain cases and one ammonite!  Gives me some hope

 

 

Patience is Key when it comes to these nodules, Once you get an eye for the Irregular ones its only a matter of time before something big comes out! Good luck!