Wallace J A
Am J Phys Anthropol. 1977 May;46(3):483-93. doi: 10.1002/ajpa.1330460315.
Gingival eruption of the permanent teeth of Australopithecus, Paranthropus, and early Homo, diagnosed from enamel scratches and facets, is similar save for two sequences: eruption of the canines relative to the premolars which may be sexually dimorphic; and agenesis of M3 with delayed eruption of M2, first seen in Homo at two million years. Gingival eruption sequences are similar also for early and modern Homo, except that in some individuals today M3, M2, M1 and I2 take longer to form and emerge through the gingiva as functioning teeth. Probably, from two million years to the present in the evolutionary history of Homo dental development slowed-down. More and more of ontogeny has been taken over for eruption.
南方古猿、傍人及早期智人恒牙的龈萌出情况,根据牙釉质划痕和小平面诊断得出,除了两个序列外相似:犬齿相对于前磨牙的萌出情况可能存在性别差异;M3缺失且M2萌出延迟,这在距今200万年前的智人中首次出现。早期智人和现代智人的龈萌出序列也相似,只是如今在一些个体中,M3、M2、M1和I2作为功能牙形成并穿出牙龈所需的时间更长。或许,在智人的进化史上,从200万年前至今,牙齿发育变慢了。越来越多的个体发育过程被用于牙齿萌出。