Echinoid parts, Jurassic, Oxford Clay

[Ossicle]

I'm trying to determine if these are echinoid.

 

I found these two on an Oxford Clay trip yesterday, Jurassic,  Callovian, Peterborough Member, near Yaxley in Cambridgeshire.

 

The first is, I think, a partial echinoid spine. My only doubts are because it's quite different from the others I've found at the site, it's a very different pattern. I would appreciate another opinion.

 

The second has completely confused me. It looks black, so I thought it was pyrite, but when I photographed it, it's clearly a completely different material.

 

It's a very odd shape, like a tiny snowman, and the only thing I thought it might be is a mamelon from an echinoid tubercle. I don't have anything else like this, and the different material puzzles me. I would really appreciate opinions on this.

[R0b]

The “white” one is indeed a partial echinoid spine. I found similar ones in France. The black one looks more like a concretion.

[Ossicle]

Thank you!

 

And sorry the images went out of order.

[jpc]

I agree... the white  one is indeed a piece of echinoid spine.  The black ones... I think they are rocks.