What species is this seashell?

[Darko]

I found this one today in marlstone of Popovac, and i would like to know which species of seashell is this? 

[gigantoraptor]

Seems like some kind of oyster to me?

[Darko]

Just now, gigantoraptor said:

Seems like some kind of oyster to me?

Maybe. 

[Guguita2104]

I agree with oyster, but preparation would be necessary if you want a more specific Id.

Regards,

 

[Darko]

1 hour ago, Guguita said:

I agree with oyster, but preparation would be necessary if you want a more specific Id.

Regards,

 

Ok thanks!

[abyssunder]

It looks like a mytilid (maybe Mytilus ) valve.

[Darko]

10 hours ago, abyssunder said:

It looks like a mytilid (maybe Mytilus ) valve.

Thanks for info!