Sifrhippus was a species of horse about the size of an average duck and roamed North America 56 million years ago.
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A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
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The oldest known animal in the world was 'Ming' the 405 year old clam, discovered in 2007.
492
When a drone bee mates with a queen, its ejaculation is so powerful that it can even be heard by the human ear.
5