Cleanly modeled (all quads) Clam shell or Giant clam shell
Rigged and animated to open and close.
Rendered with Octane Render using basic stock materials. You can apply your own materials if you don't have Octane for 3DS Max (it will alert you when you open the file in MAx and you can ignore this and apply your own materials.)
This is a quad poly subdivision model and is not collapsed in the Max version so you can dial down the poly count in 3DS Max (and possibly also the FBX file, if your application can import it with the smoothing modifier on top). Poly count and Vert count listed are for the model at the highest smoothing (level 3). Wavy sand floor is included with the model as a bonus but is not added into the listed poly count.