Early American humans hunted car-size armadillos and used their shells for houses.
12
By weight, Bone is five times stronger than steel.
417
On average, there's 100 billion neurons in the human brain.
83
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
139
Fingers prune underwater not because of them absorbing the water or washing away the oil, but because of an evolutionary trait caused by the brain to enhance the grip of your fingers underwater.
24
Your thumb is about the same size as your nose.
124
Our brains have a negativity bias and will remember bad memories more than good ones.
15