1 .		The early ancestors of horses, which lived about 55 million years ago, resembled dogs in their general appearance and were probably only about 15 inches high.    parallel   needs revision
2 .		They had arched backs, noses that looked like the snouts of pigs, and their feet were oddly shaped.     parallel   needs revision
3 .		About 35 million years ago, the average height of the horse was about 20 inches, and both its front and back feet having three toes.     parallel   needs revision
4 .		Over the next 20 million years, horses continued to grow, gradually acquiring the size, weight, and speed of today's animals.     parallel   needs revision
5 .		During the horse's evolution, its middle toe was at one time the longest of three toes, its side toes became short bones, and the middle toe began functioning as a hoof.     parallel   needs revision