The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Cows can sleep standing up, but they can only dream lying down.
745
The Lion's Mane Jellyfish is the largest jellyfish in the world. They have been swimming in arctic waters since before the dinosaurs (over 650 million years ago).
12
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
There is a persistent storm in Venezuela that produces lightning 140 to 160 nights a year, 10 hours per day and up to 280 times per hour and has been going since at least the 16th century.
25
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
The University of Oxford (teaching since 1096) predates the Aztec empire (1428 - 1521).
14