Amar is making a cladogram. Out of all the species he is using, he knows that species X and Y are the least primitive and are the most closely related. Where will these organisms most likely be placed on the diagram?

Fossils of ancestors of the modern horses show a small 4-toed almost dog-like browsing animal named eohippus over time the horses got larger lost toes and changed to a grazing diet what is the best explanation of why this change occurred