petrified coral?

[topatopa]

Found at 1000 ft elevation in the coastal foothills of Ventura County, (Southern) California (34.305441, -119.195121). I only brought home and cleaned up 3 small pieces, but they appear to have broken off the larger piece shown (outdoor photo). I stumbled upon this poking up out of the surface soil. I know nothing about fossils but I'm very cuious and am grateful for any help identifying. Thank you.

[PaleoOrdo]

Is this from Paleocene age? 

[topatopa]

My research on macrostrat.org indicates the area is part of the Las Posas Formation, which is Pleistocene.

[Myrmica]

These look like infillings of burrows, possibly 'teredo' borings.  Is this a marine deposit?

[topatopa]

Thank you for respondng. That makes sense! I believe it is marine, as there are many shell fragments all through the soil in this area (I have no background knoweldge in this, but am very curious). Here are photos of the other rocks and/or fossils in the same spot. There are also rocks with boring holes in them, so it could be infill from Pholas dactylus.