Hell creek possible ceratops frill and other bones.

[Alex S.]

Hey everybody, on my most recent excursion in the Hell creek formation ear the powder river in montana. I found some pieces of weathered out bone all in a 5 foot radius of each other on a small rise. Due to changing weather and approaching night I didn't have the chance to uncover anything else so I grabbed the weathered out pieces and will come back to the site in August.

I am a beginner and am honestly stumped as to what these could be. The 2 largest bone fragments measure 22x10.5x2.5cm and 12.8x7.3x2.9cm respectively. I am inbetween chunkasaurous or a possible ceratopsian frill. But I don't see the pronounced blood grooves frills are supposed to have. For the next largest bone fragment measuring 10x3.7x2.0cm I was thinking a vertebral process, rib, or the edge of a frill, the rounded edge on it has the same sized round as the one present on the largest bone. The rest I have no idea the smallest pieces have some interest patterning that look like some patterning I've seen or turtle shells from hell creek but these are really small. I know @Troodon has been a wonderful help before but I'd love anyone elses opinion if they can be identified or are just a lovely addition to my chunkasaur collection. 

[hadrosauridae]

The smallest ones are bits of turtle shell.  I dont think you'll a better ID on the rest than chunk-O's.  They look like they were heavily weathered / tumbled before deposition.  I agree that I dont see the expected blood grooves for the large piece to be frill, but thats not a 100% diagnostic element for a small piece.  Could also be a partial scapula or pelvic portion.

That area deserves another look in the future for sure!

[Alex S.]

Thank you @hadrosauridae, I'm really glad I was on the right track with those turtle shells.

[Troodon]

Yes agree, they could be but I would have expected some evidence of blood grooves and none are present.

[Alex S.]

Thank you @troodon into the chunkosaur display.