At up to in length and or more in weight, it is the largest organism ever known to have existed.

Onychophora are the only organisms known to produce this latter substance.

It says that small organisms (called germs), also known as microbes, cause diseases.

They are the first multicellular organisms known to spend their entire lives in an oxygen-free environment.

Because for all its apparent frailty, the human child was one of the toughest organisms known to exist.

P. dubium reportedly has the largest genome of any organism known.

Bacteria belong to the grade of organisms known as prokaryotes.

So perfect that it was one of the most feared organisms known to man.

Pollia is the first organism known to show such random polarization of light.

The two organisms are dependent on each other and live as one organism, known as a lichen.