I found this rock near Capitola, California. The rock is about 7 inches across. I am pretty sure that the fossilized shells are about 3-5 million years old because it was found near a well-known formation. However, I am wondering if that is bone in the rock. Any ideas??
@rebecca-mussetter If this were a game show, my first guess would be a coral. That is what the texture most looks like to me. Can you see any of it coming out of the other side? It’s possible that it could be the porous area, maybe around the skull of a vertebrate. With all of the invertebrates, I would guess whale. (Like from a whale fall where invertebrate organisms colonize a dead whale skeleton.)
I agree with @rnarducci . That chunk is similar to some stuff that you can find in Virginia. I don’t see any bone in it. Lots of shells, and that big eroded thing in the middle with the radial striations looks like coral to me. In Virginia, bone chunks and shark teeth can be found in that hard “greensand” rock, so I would say keep looking!