Possible Crinoid Piece? (Likely Rhomberifan)

[Kane]

While doing some prep on some Neuville Fm material (U. Ordovician, Quebec), on the slab I was working I bumped into this. Roughly 5 mm wide. 

 

I am thinking crinoid bit, but not quite sure. It doesn't seem to match the main four found there, or possibly a component piece that baffles my crinoid-poor knowledge!

 

***EDIT: Looking over the faunal lists, the star-shaped plate makes it a good match for a rhombiferan.***

 

[Al Dente]

It looks like a plate from a cystoid or pleurocystites. Here's one from the Fossil Forum- http://www.thefossilforum.com/index.php?/gallery/image/14618-pleurocystites-squamosus/

 

 

[Al Dente]

The parallel lined structure looks like a pectinirhomb- https://www.google.com/search?q=pectinirhomb&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiPtdjg27zuAhVnF1kFHQ3NDQUQ_AUoA3oECAYQBQ&biw=1350&bih=640

[Kane]

My thanks! Finding even a tiny fragment of a rhombiferan in this particular material is quite cool (although they are far more common in other locations of the Trenton Gp).

[FossilDAWG]

I agree it is a pectinirhomb of a Cheirocystites or similar rhombiferan.  Not a Pleurocystites though, the pattern of ridges is wrong.  Nice! 

Don

[Kane]

Definitely a match!

And here is a complete Cheirocystites anatiformis (MPEP 389.4) in my friend Mario's museum, collected in the same formation: