Animals began to settle on land once microbes and plants provided food and habitats. The first terrestrial arthropods included eurypterids making brief trips from shallow water to shore. They already had legs but faced challenges breathing and walking in thin, dry air. Over millions of years, many animal groups made the move from water to dry ground. This early arthropod, Eurypterus remipes, will be on display in “The David H. Koch Hall of Fossils—Deep Time,” opening at the Smithsonian’s National Museum of Natural History June 8.
Credit: James Di Loreto, Smithsonian Institution