Early American humans hunted car-size armadillos and used their shells for houses.
12
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your thumb is about the same size as your nose.
124
Your heart will pump about 212 million liters in its lifetime.
26
Your fingernails grow faster in summer.
744
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Some monks can increase their body temperature so much they can dry soaking sheets in a freezing room!
31
