The only extant fossils in New Hampshire date from the Devonian
periods, from about 400 to 300 million years ago. Brachiopods--small, shelled, ocean-dwelling creatures closely related to modern bivalves--were especially common in this state.
Many people are unaware that corals are actually small, marine, colony-dwelling animals, and not plants. Hundreds of millions of years ago, prehistoric corals were common across the breadth of North America; some particularly striking fossil specimens have been discovered in New Hampshire.