Brooklyn, the western end of Long Island, is largely made up of the tailings of the last glacial advances. The terminal moraine and outwash plain are basically rubble. Some glacial erratics may have fossils, and certainly some architectural stone here and there have had their fossils foregrounded, but otherwise this is not fossil country.But the other day, I took a good look at some of the piled-up rocks of the rip-rap that acts as the borough’s bulwark against the bay. I’d passed these many times before, but this time I was drawn to a curious insect perching on them. After photographing that, I suddenly started see the boulders for the first time. I don’t know where these rocks came from, but some of them are nothing but old, very old, mud beds, absolutely littered with fossilized remains. Saw several of these button-like ones. I recognize some shells, as shells anyway, but don’t know what most of this is.
Backyard and Beyond 
Fascinating observation! Thanks for sharing this!
really wonderful
Send some photos to the archaeology dept. of a university. What you noticed might be more important than you think.