Fossil help

[Shale_stack]

Mahantango formation of the Devonian from Pennsylvania USA

[Fossildude19]

First is a strophomenid brachiopod imprint.

Second is a bryozoan. Not sure what type though.

The rest are mostly partials.  Hard to ID partial specimens.

[Tidgy's Dad]

A strophomenid brachiopod, a fenestrate bryozoan, some orthid brachiopods and a triobite pygidium.  

[Shale_stack]

2 hours ago, Tidgy's Dad said:

A strophomenid brachiopod, a fenestrate bryozoan, some orthid brachiopods and a triobite pygidium.  

There's a trilobite in there? That's so dope. which one is it?

[Tidgy's Dad]

1 hour ago, Shale_stack said:

There's a trilobite in there? That's so dope. which one is it?

The last three photos are a partial pygidium, I think. 

[Fossildude19]

28 minutes ago, Tidgy's Dad said:

The last three photos are a partial pygidium, I think. 

 

 

I don't think those are a trilobite pygidium.  Looks more like a brachiopod to me.

[Bringing Fossils to Life]

They don't look like any trilobite I've found or seen from the Mahantango; Dipleura, two Greenops species, and Eldredgeops.

[EMP]

1. A strophomenid brachiopod.

 

2. Bryozoan.

 

3. Bryozoans, or maybe a burrow/trace fossil of some kind.

 

4. Rhynchonellid brachiopods. 

 

5. and 6. look like two photos of the same specimen. Looks like a worn out chonetid, probably Devonochonetes sp. 

 

7. and 8. also look like two photos of the same specimen. Looks like the pygidium of a Monodechenella sp. trilobite. It looks like it has very faint ribbing on the central lobe that's been mostly weathered away.

 

9. Is the thorax of a trilobite, maybe an Eldredgeops rana judging by the shape of the axial lobe.

 

Awesome finds!

Edited January 23, 2023 by EMP

[EMP]

6 hours ago, Bringing Fossils to Life said:

They don't look like any trilobite I've found or seen from the Mahantango; Dipleura, two Greenops species, and Eldredgeops.

 

Yeah, trilobites are pretty rare from the Mahantango in my experience, but I have found some fragments from Dechenella sp. in it. I also know you can find other proetid species but they're very rare. Most are limited to D. dekayi, G. boothi, and E. rana. 

[Fossildude19]

37 minutes ago, EMP said:

7. and 8. also look like two photos of the same specimen. Looks like the pygidium of a Monodechenella sp. trilobite. It looks like it has very faint ribbing on the central lobe that's been mostly weathered away.

 

9. Is the thorax of a trilobite, maybe an Eldredgeops rana judging by the shape of the axial lobe.

 

30 minutes ago, EMP said:

 

Yeah, trilobites are pretty rare from the Mahantango in my experience, but I have found some fragments from Dechenella sp. in it. I also know you can find other proetid species but they're very rare. Most are limited to D. dekayi, G. boothi, and E. rana. 

 

I respectfully disagree.

I'm pretty sure the last 3 images are parts of a Spiriferid brachiopod.

Specifically the beak section and sulcus.

 

Right side

 

 

Right side:

 

 

Left side:

 

[EMP]

9 minutes ago, Fossildude19 said:

 

 

I respectfully disagree.

I'm pretty sure the last 3 images are parts of a Spiriferid brachiopod.

Specifically the beak section and sulcus.

 

   

 

I see your point on the last one in that new photo, but the other one still looks like a pygidium to me:

 

 

The "sulcus" looks more like where it's been chipped.

 

Is there a way to get a top-down photo OP?  @Shale_stack  Especially of the black blob above the main fossil?

[Fossildude19]

All 3 are the same item. 

I believe this is an internal mold, so some detail would be missing, and part of the forked beak is broken off.

[A.C.]

I agree with @Fossildude19s assessment of the “pygidium” 

 

Here are some Mahantango pictures to help clarify things:

 

Trilobite:

 

Spirifids:

Edited January 23, 2023 by A.C.

[EMP]

11 minutes ago, Fossildude19 said:

All 3 are the same item. 

I believe this is an internal mold, so some detail would be missing, and part of the forked beak is broken off.

 

Ahhh I see what you're saying. Yeah, looking at it again I think the last one's a spiriferid. The camera angle had me thinking they were different specimens. 

[Bringing Fossils to Life]

Mahantango trilobites are not very rare in some localities, with Dipleura dekayi fragments being not hard to find. Asteropygines are rare, and it depends on the time frame weather Eldredgeops is uncommon or extremely rare; at one site near the Middle Devonian Extinction only one cephalon has been found.

[Advantage]

Fascinating discussion, this is why this forum is excellent, how the discourse developed to a very likely id and conclusion to the original question.

[EMP]

23 hours ago, Bringing Fossils to Life said:

Mahantango trilobites are not very rare in some localities, with Dipleura dekayi fragments being not hard to find. Asteropygines are rare, and it depends on the time frame weather Eldredgeops is uncommon or extremely rare; at one site near the Middle Devonian Extinction only one cephalon has been found.

 

Yeah, it's sort of location dependent like you said. I've collected at a couple of Mahantango exposures fairly consistently and after several years I've only come away with a small handful of trilobite remains, and no whole ones. Go up to Virginia or elsewhere in Pennsylvania and you can find a lot more of them.