Can anyone name this fossil?

[Picklespeck]

I am new to fossils...

I found this on the rocky shore of Cabrillo Beach, San Pedro, California. 

The rock is a hard sandstone.

Any idea about the fossils?

 

[Raggedy Man]

Looks like impressions from brachiopods. Lets see what others have to say.

[DPS Ammonite]

I believe that marine rocks in that area are Miocene and newer. Brachiopod fossils (inarticulate only) are unlikely. My best guess now is that they are external molds of both valves of one clam either slightly ajar or butterflied. Take 2 or 3  better pictures each with only one fossil. Your camera/phone seems to have focused on the background and not the fossil. Try setting the rock on a table and get as close as you can to take the photo. 

 

The rock also could bear the eroded marks of recent boring marine clams. Has anyone seen clam borings with 2 lobes?

[abyssunder]

I've never seen borings with two lobes. The pebble looks to be consolidated and tumbled to the shore. Maybe it is transported material? If it contains tiny brachiopod imprints, as Paul is suggesting, could they be pentamerids? (how tiny could they be for that?).  Or, maybe, they are boring bivalve shell imprints in the matrix?

 

Coffee bean imprints for the morning?

[ynot]

I think a good name for this fossil would be Fredrick.

 

There are a lot of fossil bearing sand/silt stones along the California coast, most are tertiary.

I would say they are most likely clam shell imprints.

[Sagebrush Steve]

2 hours ago, ynot said:

I think a good name for this fossil would be Fredrick.

 

There are a lot of fossil bearing sand/silt stones along the California coast, most are tertiary.

I would say they are most likely clam shell imprints.

Yes, I agree.  I've seen other similar rocks from the coast around Palos Verdes south of Los Angeles with clam fossils embedded in them.  They are all Tertiary.  Usually there is still some shell remaining but maybe the force of wave action eroded them away, leaving only the imprints.