Explore an Era:
Where (and when) do horseshoe crabs evolve?
The evolution of the horseshoe crab extends back far before the dawn of human civilization, before the dinosaurs, before flowering plants... back to the era in our planet's history when visible life first appeared.
Our Evolution section traces the development of the horseshoe crab from the Paleozoic Era and provides an overview of the changes to our planet's geology, climate, flora and fauna from 540 million years ago to the present. Toward the end of the Cenozoic Era, beginning with the Holocene (11,000 BC to the Present), we look specifically at the evolution and development of the Delaware Bay.