He became fascinated with tiny eight-legged organisms called tardigrades, which can live in moss for more than a century.
Some of the humblest-seeming animals are also the longest-lived, like the tardigrade, or water bear.
Being able to withstand desiccation, starvation and extremes of temperature, has contributed towards the success of the tardigrades, which live in habitats from damp moss to flowering plants, sand, freshwater and the ocean.
Tardigrades have a unique metabolism that allows them to enter a state of suspended animation.
Like the tardigrades, the rotifers are multicellular animals.
The common organisms of choice to study cryobiosis are tardigrades, which are known to survive freezing to near absolute zero.
However, tardigrades are animals that have small body sizes.
In total, 15 biological species were involved including yeast, tardigrades, rotifers, lichens, nematodes and bacteria.