Help with arthropod ID

[EMP]

I found this a while ago (back in February I think) and I initially identified it as a pill millipede. Well, I got back around to examining it and after some research online I'm no longer confident with that ID. It turns out that pill millipedes didn't exist as far back as the Mississippian, and even though millipede fossils are known from the area's Devonian rocks (like at Red Hill), none of their finds are similar to mine. I understand that time difference may play a role, but still they should look generally the same. This specimen is more rounded and "squat" then the Red Hill examples and other fossil millipede specimens, and has more robust tergites (segments) on its body. 

 

I still believe it is most likely an arthropod for a few reasons, one is that I still have yet to find any plant material from this layer, two because these rocks are early Mississippian in age an no plants that would look similar exist from this period in this region, and three is because the segments on it's body are too different from the growth lines of plants and appear to be part of an armored exoskeleton rather then the result of growth as in plants. 

 

Beyond this I have no real idea anymore. I have found a trigonotarbid before in this layer of shale, but even that specimen is not quite the same as this one. 

 

I'll try and get better pictures later today, right now all I have is this. If you look carefully enough, there appear to be faint impressions of some legs to it's one side. 

[piranha]

Looks like a crinoid.

 

 

[EMP]

1 hour ago, piranha said:

Looks like a crinoid.

 

 

 

That's impossible, this is a land deposit that was miles from the ocean. 

 

Edit: Miles away in Mississippian times, not just now. The formation this is from is the Purslane Formation. If this were the Rockwell Formation then I would consider crinoid, but no marine layers are known from the Purslane and no marine fossils have ever been found in it.

[Fossildude19]

I'm afraid better pictures are going to be necessary. 

[Miocene_Mason]

my guess is milipede like this one, also Mississippian.

[EMP]

Here are some new pictures. Let me know if you want some more:

 

The last photo is not mine. It's from an older thread of mine of a trigonotarbid specimen another forum member had found. The body structure seems similar to this one he found, but any other thoughts?

 

 

[Kane]

There doesn't seem to be enough detail to make this out with any accuracy.

 

This might be one of those cases where an accurate ID may only be possible by having the specimen in hand. Alternatively, if you could get a hold of a USB microscope, that might help to really home in on the specimen and better bring out the detail.

[Fossildude19]

I'm not even really seeing anything fossil related here. 

I can't really make out any segmentation. 

But, other's may see what I cannot. 

 

[EMP]

18 minutes ago, Fossildude19 said:

I'm not even really seeing anything fossil related here. 

I can't really make out any segmentation. 

But, other's may see what I cannot. 

 

 

If you look at the pictures without zooming them in you should be able to see a few, thin, darker gray lines (almost brownish) that separate a few lighter gray, and larger, segments. Especially in the third one zoomed out (may need a while). If you zoom too far in then it becomes blurry.

 

Definitely in person the segments are there, I can't figure out why my phone won't pick up any details. I do have a proper camera now, but it isn't working .

 

 

[FossilDAWG]

Try taking a photo with the lighting coming obliquely from the side, so as to create shadows to emphasize any surface features.

 

Don

[Fossildude19]

Well, I can see the lines you are talking about, but better pictures are needed before I go and make an id on this.

 

Good pictures should show the details you are seeing with the rock in hand.

 

[Miocene_Mason]

Here it is cropped and enhanced

[Fossildude19]

Still blurry - I see the lines, but no crisp detail defining "segments". 

In this photo, it just looks like staining to me. 
Try to borrow someones camera - your phone just isn't capturing the details. 

[JohnBrewer]

I can't see anything at all here. You could try using a flatbed scanner and scan it. Two advantages, light comes at an angle and the quality is pretty good if you scan at a high resolution. 

[doushantuo]

That's indeterminable

[jpc]

I also don't see anything fossily.  

[Sagebrush Steve]

57 minutes ago, WhodamanHD said:

Here it is cropped and enhanced

Is the feature concave into the matrix or convex rising above it?  Hard to tell from a 2-dimensional photo.  My initial assumption was concave, in which case it looks vaguely like the impression from a millipede, but I'm not sure there is enough there to be definitive.  Could you give some indication of the dimensions of each of the individual segments (I think I see 5, possibly 6 segments)? I do see a couple of marks on the upper left side that I think are what you suggest might be legs but I'm not sure, they could just be coincidental features.  And what is that parentheses-like feature of the left, could that be significant?

[EMP]

23 minutes ago, Sagebrush Steve said:

Is the feature concave into the matrix or convex rising above it?  Hard to tell from a 2-dimensional photo.  My initial assumption was concave, in which case it looks vaguely like the impression from a millipede, but I'm not sure there is enough there to be definitive.  Could you give some indication of the dimensions of each of the individual segments (I think I see 5, possibly 6 segments)? I do see a couple of marks on the upper left side that I think are what you suggest might be legs but I'm not sure, they could just be coincidental features.  And what is that parentheses-like feature of the left, could that be significant?

 

It is concave (as in, shaped like a bowl). There are five segments, with another couple of smaller ones near the "front" of the specimen (I say this because not every arthropod has the same body plane, and those could be the rear of the head region if it were a trigonotarbid and not millipede).

 

In terms of size of the segments it's hard to say exactly, because the whole thing is around a quarter of an inch long. I tried outlining the body in red. The circles to the left are the "legs". In life the "'parentheses'" figure is a chip of shale.

[Missourian]

There are some intriguing details. The presence of spiders in the same bed is quite encouraging.

 

It's too bad your phone (I'm guessing iPhone) does that 'noise reduction' (a.k.a detail reduction) that gives a 'watercolor' effect. My new SE does the same thing.

[EMP]

1 hour ago, Missourian said:

There are some intriguing details. The presence of spiders in the same bed is quite encouraging.

 

It's too bad your phone (I'm guessing iPhone) does that 'noise reduction' (a.k.a detail reduction) that gives a 'watercolor' effect. My new SE does the same thing.

 

Actually an Android, but yeah I hate it. And a lot of my fossils are so small, there's no possible way to get good details of them with this effect.

 

Hopefully someone with more knowledge/experience of arthropods can chime in, because these are out of my comfort zone. I've been trying to learn some things about them, but I still am quite novice at it. I'm more good at geology and giving general IDs on more common things.

 

 

[Miocene_Mason]

Although you do say the deposit was far from the ocean, closer to your original guess, it could be an early terrestrial isopod (colloquially known by many names, such as pill bug, rolly Polly, and such as well as woodlouse). I found this on Wikipedia:

"The fossil record of isopods dates back to the Carboniferous period (in the Pennsylvanian epoch), at least 300 million years ago, when isopods lived in shallow seas" 

did not mention when they evolved into land faring creatures, but I'm sure it could be uncovered through some research 

[Miocene_Mason]

Well here we are, pill bug, not millipede, is a possible candidate. It's not a large leap to Mississippian, of it is one it would be of scientific significance.

https://www.researchgate.net/publication/235964395_The_origin_of_terrestrial_isopods_Crustacea_Isopoda_Oniscidea

[Miocene_Mason]

I'm gonna ask some people that are familiar with the living members and see what they think.

[EMP]

6 hours ago, WhodamanHD said:

I'm gonna ask some people that are familiar with the living members and see what they think.

 

Let me know what they say!

 

Isopods seem like an interesting choice. Apparently there was one species found that's believed to be a terrestrial isopod from the upper Devonian, so in theory there's the possibility of it being a land isopod. However, it's status looks like it's disputed so then again maybe not. Interesting read nonetheless, and it shows how speculative and painful the consideration is that goes into this science.

I managed to find a plate of the upper Devonian bug. It's on page 261. Not the best photo quality however, but consider this was from 1903.

 

https://books.google.com/books?id=9DoXAQAAIAAJ&pg=PA258&lpg=PA258&dq=oxyuropoda&source=bl&ots=wk_2v2GJHv&sig=13bE1rVOO2ejEJNdWVeF6R66HnM&hl=en&sa=X&ved=0ahUKEwj4x8D8sJHUAhUBWSYKHfbRDm4Q6AEIKDAB#v=onepage&q=oxyuropoda&f=false

 

 

[Kane]

Given the challenges with pictures, it may be time to consult an expert at your local university so the specimen can be viewed in-hand. Once you do, keep us updated.