It’s made of keratin—that’s the stuff your hair and nails are made of. The horn is a pretty distinctive feature—the name “rhinoceros” is actually made of two Greek words meaning “nose” and “horn”. Tragically, rhinos are often killed for their horns. The once-large rhinoceros family has dwindled to just a few living species almost all of which are threatened with extinction.

• An extinct species of hornless rhino was the largest land mammal of all time. Standing 5.5 metres at the shoulder, this gigantic animal lived in western Europe and Asia about 35 million years ago.

• The white rhino’s colour is basically gray. The name may come from a mis-translation of an Afrikaans word for “wide” which refers to its lips or from the fact that the first such rhinos seen by Europeans were wallowing in light-coloured mud.