I remember way back in my college days(+30 years) I used to take my students out in the field to collect fossils.
The scoured the location and promply brought back fossils for me to identify. Always some one would
bring me back an unusual fossil which was quite recent in age. I would say "Recent coprolite". When they
looked puzzled I would then say "Rabbit Turd"
the shell am talking about it was encrusted in a rock like type but I was able to take out of it, the other shells are fossilized but for a reason not this one I have try to take a picture if ot but I dont have a good camera.
I CAN HOLD IT IN MY FINGERS IS REALLY NICE.. SIZE = 1/4 OF INCH.