Fig. 3

A hypothetical animal which, during its ontogeny, undergoes a number of morphological changes. Peramorphic descendants develop “beyond” the ancestor; padomorphic descendants retain juvenile ancestral features. In hypermorphosis, growth stops later; in acceleration, the horns and tails grow faster; in predisplacement, the horns and tail start growing earlier. In progenesis, growth stops earlier; in neoteny, the horns and tail grow at a slower rate; in postdisplacement, the horns and tail start their growth relatively later. Reproduced with permission from McNamara (1997)