The invention of the wheel is a major breakthrough in human history. But now, the records may have to be rewritten - as the earliest evidence of wheel use has been pushed back 6,000 years.

They are used to help things move. A wheel is a round, flat object made of a hard material. An axle is a rod that passes through the centre of the wheel.

What is an axle? An axle is a rod that passes through the centre of a wheel. The wheel grips the axle tightly, so the wheel and axle turn together. Axles help wheels stay in place and spin smoothly.