Cretaceous ID needed

[Gen. et sp. indet.]

Two specimens from the Campanian of southern Poland.

 

[Gen. et sp. indet.]

Specimen No. 1 - unknown ?encruster with attachment frills? and rugged ribs

 

[Gen. et sp. indet.]

Specimen No. 2 - two? bivalves: spiny ?spondylid with attachment frills? attached to a smaller ?spondylid

 

 

[Gen. et sp. indet.]

Specimen No. 2 - continuation

[Tidgy's Dad]

They do look like spiny spondylid bivalves. 

I think what you have there is that the outer mineralized and replaced shell has been broken away in some places to reveal the internal mould underneath. 

Thus it appears like one inside the other. 

Except for the last couple of shots that show a couple of specimens near/ overlapping each other. 

Nice finds!  

[Gen. et sp. indet.]

Thank you for the answer!

1 hour ago, Tidgy's Dad said:

the outer minerlized and replaced shell has been broken away in some places to reveal the internal mould underneath. 

Thus it appears like one inside the other.

Yes, I know that! I was referring to the specimen No. 2, which clearly shows a smaller individual on one side of the larger.