This is because the size of the foot is an essential characteristic of the species, for no animal has the tarsus and metatarsus combined so small as man; hence the uprightness of his gait: he is a plantigrade.
"Essays of Schopenhauer"
Arthur Schopenhauer
All the known species of deer can be classified under these two heads; and it is a significant fact that this pedal division is borne out by certain cranial peculiarities discovered by Professor Garrod, and also, to a certain extent, by an arrangement of hair-tufts on the tarsus and metatarsus.
"Natural History of the Mammalia of India and Ceylon"
Robert A. Sterndale
In the Old World deer, which are with few exceptions Plesiometacarpi, those which have these tufts have them above the middle of the metatarsus, and those of the New World, which are, with one exception, Telemetacarpi, have them, when present, below the middle of the metatarsus.
"Natural History of the Mammalia of India and Ceylon"
Robert A. Sterndale