Why horses have one hoof
A horses’ hoof is essentially a single, giant inflexible toe, quite different to their ancestors which were dog-sized creatures with three toes.
This comes from new research, showing how the horse adapted to living in grasslands and became the animal we know today.
The single hoof used to be a middle toe of three, which expanded and became rigid while the side toes dwindled to nothing. The researchers used 3D imaging of fossilised horse legs to show how the middle toe became stronger to cope with bigger body sizes.