origin: (1860) Latin tardigradus= slow-moving, from tardus= slow + gradi to step or go
No, this isn't related to Dr.Who and his TARDIS, but by golly gum it could!
Their nickname is "water bear" due to their stout shape, and distinctive sets of four legs, which end in claw-like appendages. Tardigrades are microscopic and one of the hardest things in the universe to kill that we know of! Neither freezing, or boiling, or even the radiation of outer space does them in -- we've tried!
In any situation where there isn't enough to sustain a tardigrade, they simply enter a state of "cryptobiosis" (or stasis), like a vampire emerging when the time is right and can last hundreds of years in such ways.
Where can you find water bears? Everywhere!
These sturdy, tiny, invertebrate critters enjoy lumbering around in mosses, lichens and sand grains: 900+ species of tardigrades live in freshwater & about 10% in the sea. As they can survive in outer space, some scientists speculate that it's even possible they originate from outside our own solar system!!
origin: Romani trovanti, via Germanic Sandsteinkonkretionen= "concrete masses of sandstone"
Weird as a "water bear" is, this is something that entirely defies science or life as we know it. You are looking at living stones. You read that right. And you probably didn't know they've been living in Romania all this time!
Why aren't they everywhere? Well, because they were created under very unique circumstances; it is said they erupted from very deep earthquakes that took place over six million years ago. After heavy rains, these stones grow 6-10 millimeters, slowly over time ripening to 6-10 meters sum total! Scientists say this growth is caused by "mineral salts" inside the trovants bodies causing them to swell.
The rocks are also said to often move.
But other rocks on Earth do this as well.
However, what really cannot be explained is how these rocks are reproducing. And if you know something about the definition of life...you'll know that's an important part of it. Inside each sphere are rings, like inside of a tree, indicating periods of growth. When new spheres appear as small bumps, they grow to a certain size on the body of the "parent" and then break off due to weight; the baffling part being how these youngsters formed a new core if the trovant's growth is nothing more than a chemical reaction to an ancient cement batter (a.k.a. diagenesis). Or could it be they represent a non-organic form of life?!
I seem to cover this sort of topic often, so if it interests you as well, feel free to click the tag wordsmith:theidolhands or scientific in this entry.