Did horse feet evolve for endurance travel at the trot rather than speed at the gallop?

Fight or flight. Run or be eaten. We were all taught that horses evolved to have single toes because they were the prey of predators. A single hoof made them one of the fastest animals on earth. The successful survivors were the fastest ones, because they could outrun lions and tigers and bears. But a new group of researchers published an alternate point of view on April 12, which we share thanks to the University of Bristol in England. According to the authors, they weave "together information from equid evolutionary history, foot anatomy, and locomotion, which provide the essential background information that informs our novel proposition". They suggest that horses' feet evolved for efficient trotting during grazing, rather than for speed to evade predators. But isn't it possible that the single toe aided both survival gaits?

Hidden Anatomy: Researchers Make a Case that Modern Horses Have Five Toes--Even If We Can't See Them

One of the keys to the Solounias research is the leafy construction of the Eponychium hoof covering in the fetal horse. The researchers dissected fetal hooves and paid close attention to the construction of the Eponychium. From left: Medial view of fetal horse hoof;  Dorsal view of the fetal hoof, showing a smooth singular surface, representing the dominant digit III; Ventral view of a fetal horse specimen, showing four distinct infoldings that depict evidence of the Solounias paper's proposed digits I, II, IV and V.  (Detail from one of the many figures in the article.)

Scientists have long wondered how the horse evolved from an ancestor with five toes to the animal we know today. While it is largely believed that horses simply evolved with fewer digits, researchers at New York Institute of Technology College of Osteopathic Medicine (NYITCOM) pose a new theory suggesting that the remnants of all five toes are still present in the distal limb of the horse.