This tiny creature may not look spectacular, but it is one of the most remarkable ever discovered: the first that can survive and reproduce entirely without oxygen. Assigned the genus Spinoloricus, the animal is less than a millimetre long.
The beasts live in conditions that would kill every other known animal. As well as lacking oxygen, the sediments are choked with salt and swamped with hydrogen sulphide gas.
None of the animals has mitochondria, the “power stations” that generate energy from oxygen in the cells of all oxygen-using organisms. Instead, they rely on structures called hydrogenosomes, which generate energy from molecules other than oxygen, including hydrogen sulphide.
Given the variety here on earth, probably.