Carboniferous arthropod trace fossil?

[Allodon]

I found this rock alone under a tree, so I'm pretty skeptical of it, but I'm also pretty curious. I looked up trace fossils that might look like this, and I thought it was pretty similar to Rusophycus. The rocks around it are from the Glenshaw and Cassleman Formations of late carboniferous Pittsburgh. The "print" is about 10 cm long in its entirety, and maybe a quarter cm deep or so. Could this be a print of sorts or is it just some funky weathering?

 

Thanks!

[Allodon]

A couple more angles of it 

 

[Top Trilo]

Im not sure if it is a fossil. Is it concave or convex? The first pictures look convex but the last one looks concave. 

[Allodon]

It's concave, its just a matter of lighting on that one I guess

[westcoast]

Looks like the trace fossil Psammichnites

[Rockwood]

Or Rusophycus ?

[Top Trilo]

4 hours ago, Rockwood said:

Or Rusophycus ?

I searched a picture of both of them and this one seems to fit best,

 Psammichnites

Rusophycus

[Fossildude19]

I'm not convinced this is a trace fossil. 

The edges of it are a bit jagged. It looks more to me like a fracture pattern .

I don't see any definite ridges where trackmarks would show.

I think this is just the way the rock fractured, then weathered.

 

         

[Rockwood]

Black fractured geology. Blue trace fossil.