I picked this up a while back. It was part of an old collection and identified as a coprolithe (aka coprolite). After rinsing it off and looking at it under the microscope, I'm thinking it is some sort of burrow. It contains what looks like invertebrate fecal pellets and fishy bits. I am trying to figure out what this little inclusion is. I was thinking it is a bit of fish skull or possibly a crustacean bit. Anyone recognize it?
Thanks for your help!