Tardigrades

Tardigrades ( ), also known as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them Kleiner Wasserbär 'little water bear'. In 1776, the Italian biologist Lazzaro Spallanzani named them Tardigrada, which means "slow walkers".

Tardigrades live in diverse regions of Earth's biosphere: mountaintops, the deep sea, tropical rainforests, and the Antarctic. They are among the most resilient animals known, with individual species able to survive severe conditions – such as exposure to extreme temperatures, extreme pressures (both high and low), air deprivation, radiation, dehydration, and starvation – that would quickly kill most other forms of life. They have survived exposure to outer space.