The Specializations of Man and His Place Among the Catarrhine Primates

From all comparative-anatomical knowledge it has become abundantly proved that man belongs to the suborder of simian primates. This suborder is readily and naturally divided into two distinct, main groups, namely, one of the New World and one of the Old World. The animals of the first group possess without exception three premolar teeth on each side of both jaws, whereas those of the second group have only two of such teeth, and the former lack a bony auditory canal which develops in all the latter during postnatal life. On the basis of these and numerous other, constant anatomical differences between the American, or platyrrhine, and the Old World, or catarrhine, primates man must be assigned to the latter group. No fossil catarrhine has ever been discovered in the Western hemisphere, nor any fossil platyrrhine in the Eastern one, hence it must be assumed that the separation between these...