Featured on PDR in the collection Among the Moss Piglets: The First Image of a Tardigrade (1773)

The tardigrade’s tiny size belies both its astounding physical resilience and its charisma. Also known as water bears or moss piglets, they can survive extreme temperatures and pressures, withstand radiation levels that would kill most organisms, and reanimate after long periods of desiccation or oxygen deprivation. They can even handle being in outer space without too much trouble — impressive for creatures that are roughly the size of a grain of sand. As a result, the 1300 known species of tardigrades are found everywhere on Earth: from the deep seas, to rainforests, to Antarctica.