Rudists' casts ?

[Quer]

 

Hi everyone,

 

Some weeks ago, I found those pair of pieces at the foot of a Pyrenees cliff (Maastrichtian limestone strata), which was stuffed with rudists (radiolidae).

They have an extremely smooth surface that confused me.

 

After some fantasies about teeth, bones and so on, I realized that the clue had to be around.

My ID guess is: rudist's (radiolitidae) casts, separated from shell by wheatering and erosion.

I'll explain it with some pictures taken at the same place, inserted in a fictional sequence (I do not intend they are same species or genus):

 

 

Do you think my guess is correct ?

 

Thanks,

Edited February 12, 2018 by Quer

[abyssunder]

You are correct. Those are the "cores" of rudist lower valves, the sediment infilled body cavities.

[Tidgy's Dad]

+ 1 for your guess they are rudists. 

[fifbrindacier]

Hi, neighbour, i also agree with rudists.

[FranzBernhard]

Yes, like abyssunder said, these are inner casts of the lower valves of radiolitid rudists.

Are there fragments of the upper valve in one ot the images? I have found such a cast myself in my area, with the upper valve still attached.

Franz bernhard

[Quer]

Thanks to everyone, my little enigma is solved.

 

I fear not, Franz. In fact, I have a few complete rudist pieces, some upper valve pieces, but they are Hippuritid pieces (well, I think).

Radiolitid upper valves are the rarest thing. I only have this little fragment:

 

 

Btw, I'm working on this upper valve. It shows clearly its structure of canals & pores, and maybe its teeth & myophore can be found below.