Michigan also selected an official stone that year, though it didn't become official until 1966. You see, Petoskey stones are actually fossilized corals. Today, most states have official fossils, and they aren't ashamed to call them state fossils. The first genuine state fossil was Nebraska's mammoth, which was adopted in 1967. It was also a fairly unusual state fossil.
Marine invertebrates are especially popular in the eastern United States and the Midwest.
Wisconsin, Ohio, and Pennsylvania are represented by trilobites. Maryland's official fossil snail and neighboring Virginia's prehistoric scallop are especially historic. Virginia's was even named for Thomas Jefferson, who was a famous fossil fan. Kentucky's official fossil is another bivalve, the clam-like brachiopod. Delocrinus missouriensis . .