The winds along Lake Michigan reveal many buried fossils I often find that I like to share with you, but sometimes they are a complete mystery. My hope is that somebody can wage a guess or provide a knowledgeable answer about the following mystery fossils below in the comment box.

UPDATE: C. Chavez wrote me about Mystery Fossil #2: I believe your “Mystery Fossil 2″ is not a fossil, but a reductive rock. If you were to crack it open you’d find the perfect circle is actually a sphere. It is created by some foreign material that is introduced into the rock which results in bleaching. It is the same idea as if you were to put a drop of bleach on blue jeans and it would expand into a circle. We have many reductive rocks where I live in NM, but they are not common elsewhere. You can find me and many more people helping to identify fossils at “thefossilforum.com”. Thank you C. Chavez

Update: The fossil above is a section of an extinct soft shell turtle