Minnesota's state fossil revisited

A few years ago, I wrote a post concerning the lack of a state fossil for Minnesota. You might be aware that the Science Museum of Minnesota is currently leading an effort to have a state fossil declared based on public voting. You can check out the candidates and vote here. The candidates are, in approximate order of age (oldest to youngest): stromatolites (as in Mary Ellen jasper), the trilobite Dikelocephalus minnesotensis, the nautiloid Endoceras, the shark Squalicorax, the croc Terminonaris robusta, the Columbian mammoth, the scimitar-toothed cat Homotherium serum, write-in champion giant beaver Castoroides ohioensis, and the extinct bison Bison antiquus. Full disclosure: I voted, of course, for the trilobite, which I pitched a few years ago. Voting closes September 30, so there's still time to participate.