Amazingly, Michigan's fossil deposits stretch all the way back to the Cambrian
period, about 500 million years ago. In this state's oldest sediments, you can find the tiny, fossilized remains of ancient algae, complex, single-celled, ocean-dwelling organisms that attain macroscopic size by joining together in colonies.
2. Small Marine Animals
For over 200 million years after the Cambrian period, the state of Michigan was covered by a shallow sea. That's why sediments from the Ordovician
periods are rich in small marine organisms, including various species of corals, brachiopods, trilobites and crinoids (tiny, tentacled creatures distantly related to starfish).
3. Prehistoric Whales
For the past few hundred million years, most of Michigan has been above sea level--but not all of it, as evidenced by the discovery of various prehistoric whales
, including specimens of still-extant cetaceans like Physeter (better known as the Sperm Whale) and Balaenoptera (the Fin Whale). These fossil whales are extremely recent, some dating to less than 1,000 years ago!