I'm waiting for Math Club and am trying my best to stall and not be productive. So I looked this up:
Look closely at the period ending this sentence. Scientists have discovered a bacterium similar in size to that punctuation mark, making it the biggest ever observed. In terms of cell volume, some copies of the bacterium are more than 100 times larger than the previous record holder.
"I'm stunned by how big this thing is. This goes orders of magnitude beyond what I thought was possible," remarks microbiologist Mitch Sogin of the Marine Biological Laboratory in Woods Hole, Mass.
Residing in the greenish ooze of ocean sediment off the coast of Namibia, the spherical bacteria have diameters ranging from 100 to 750 micrometers (that's .1 to .75 mm). Since the bacteria often form strands of a dozen or so cells and glisten white from light reflecting off sulfur inside them, scientists named the microbe Thiomargarita namibiensis, or sulfur pearl of Namibia.
It's comparable to the size of the head of a fruit fly.