Why this world is so damn awesome:
The oldest living thing seems to be a bacteria found in ancient sea salt underneath Carlsbad; New Mexico. The organism was revived after being in suspended animation for, hold on, 250 million years! That's older than the continents! Here's a picture of the bugger
A type of fern found in Queensland; Australia, will never spread beyond its current distribution. The reason? The species it depended on to carry its seeds died out with the dinosaurs.
If you round of the decimals (even to what would still be a rather good accuracy), you would be telling the truth if you claimed that 100% of the species on earth are unkown to us.
What makes us human? Certainly not our bodies! The number of human cells in the body is outweighed by the number of bacterial cells by a factor of 10. That is, we have an estimated 10 trillion human cells inside us, but a whopping 100 trillion bacterial cells!