Mars Clam Bed?

Here is a picture from Opportunity.  Don't these shapes remind you of different kinds of clams?

Wouldn't one expect there to be clams in a Martian ocean?

Some of the clams appear to be round, some oblong and even some appear to be on edge, showing the two parts.  Look at the upper right hand arrows.  They appear to point to a clam that is turned on its edge.  You can see the same feature at the first down arrow in the top left corner.  Right beside it appears to be a scallop shaped object with a nice rounded clam below it. Some of the objects appear to have radiating lines.  See the object just southeast of the scallop and west of the big "rock" in the center of the photo.   If you look at the double up-down arrow in the lower right corner, you will also see what appears to be two glassies, nestled in the Martian sands.

The first glassies appeared on the Opportunity microscopic images starting with Sol (day) 19.  Since then, almost every image has been too out of focus to even see any detail.  You'd think for $400 million, they could have put an auto focus and maybe even a color camera.

The Frass Meteorite has a small clam that is melted to the outside of the meteorite.  I think the clam was stuck to the rock as it was forming, since the lava would have been hot as it was flowing.  It probably cooled very rapidly on the surface of Mars, so the clam was not hurt much.  If you look carefully, you can see the sand that is also stuck inside the clam shell.  If you look real hard, you will see a couple of glassies laying in and around the shell.

Also notice the fusion crust around the little clam.