The unique four-beat gait of the Missouri Fox Trotter is not due to an extra vertebrae. It's a result of their unique conformation, which includes:
* Long, sloping shoulders: This allows for a longer stride and a smoother gait.
* Strong, muscular hindquarters: These provide the power for the four-beat gait.
* Flexible back: This allows for the horse's back to "rock" during the gait, resulting in the characteristic "fox trot."
The myth of the extra vertebrae is just that – a myth!