Lake Michigan Marine Fossils?

[klitz2011]

Hi everyone,

 

My six-year-old and I were out hunting for rocks along the shore of Lake Michigan in Berrien County yesterday, October 13, 2024. We found a lot of Petoskey and Charlevoix stones, but also these two suspected fossils. He's incredibly excited with my vague guesses already ("could be an ammonite, who knows!"  ) But we'd love any input from folks who are more experienced at hunting and IDing these things.

 

Thanks in advance,

Two kindergarten naturalists (one current, one emeritus)