The diagrams depict the evolunionary transformation of the horse over 40-millin-years period.
Overall, the horse had undergone four main stages in its evolunion, starting from eohippus and culminating in modern horse. Futhermore, over the period, while the horse’s size gradually increased, it’s feet continuously decreased.
By 40 million years ago, the horse was known as Eohippus, this species were very small and looked weaker than now. Their leg had about 5 toes, including the shortest one at the left beyond others. At 10 following years, the horses became grown with longer leg and tail, called Mesohippus. At this point, their feet converted into three bigger toes, with main toe at the central was biggest.
In 15 years ago, Mecrychippus was the more contemporary version of 30-million-years ago horse. Right now, the horse’s mane started growing and their muscle looked more solid which made them resembled the modern species. Moreover, during this stage, the main toe was remarkably larger being the most vital function in moving. After this period, they are known as the modern horse with tall and well-built body. Most importantly, from three toes in 15 million years, they have transformed into sole one.