My son found this in the water at Flag Ponds Park near Calvert Cliffs. Based on a quick look at some of the displays at the Marine Museum, I think it's part of a vertebra of a marine mammal. Does that sound right?
It's pretty well eroded so I assume it had been tossed around for a while and it looks like part of the exterior was broken off to show some of the interior of the bone.
I'm sure it's too beat up to know the species, but based on the shape and size (almost three inches at the widest) is it possible to guess whether it's porpoise, seal, or something else? Thanks for any input.