Bivalve? Brachiopod? Gastropod? Please ID

[itsmartyliu]

I found these while on a trek uphill. I’ve posted it on different sites but no one can give a positive ID on my finds. Location is Cebu, Philippines by the way.  Always been curious about how the ocean life was here millions of years ago as most studies indicate that the Philippine archipelago was submerged in water. 
 

For more angles, click on that imgur link as I have labelled those there. 

[FranzBernhard]

Welcome to TFF from Austria!

 

You are having some nice bivalves and gastropods there! But I can not ID them any further.

 

You may have a look at a geological map of your area, checking out in what formation these fossils were found. After that you may google for papers about this formation. Maybe some fossils are mentioned or described in that papers.

 

Franz Bernhard

 

[Ludwigia]

I agree with Franz. Assuming that you are showing us just 3 samples, I would say that the first 5 photos show us a bivalve, the next 5 photos a gastropod and the last 4 another bivalve.

[Paleorunner]

Agree with my peers.
It will not be easy to identify them without more information.

Edited July 18, 2022 by Paleorunner

[Fossildude19]

Additionally, they appear to be steinkerns, which makes ID a bit more difficult.