Mississippian brachiopod?

This post will probably be the last on this large Mississippian rock from Hodgenville, Kentucky. The lines remind me of a brachiopod shell.

Mississippian Rock with Unknown Fossil

This fossils looks like some sort of stem creature. It reminds me of a smoothed blastoid but this could be a pseudo fossil.

It is just a distinct shape but no real lines showing details.

Mississippian Rock

Here is the large rock I have been studying that came from Hodgenville, Kentucky (birthplace of American President Abraham Lincoln).

Here is a calcite or quartz cavity with Fenestella bryozoan around it.