proterogenesisn.

1938 Rep. Brit. Assoc. Advancem. Sci. 79 Among the examples quoted by Schindewolf in support of the principle of proterogenesis is one drawn from the cephalopod family the Clymendiæ which lived during the Devonian period. It consists of a number of genera and species in which, at one end of the series, the shell has the normal type of spiral coil..with an almost circular outline throughout development. In the next member of the series the innermost portion of the spiral has a triangular outline. In other members of the series the latter form of outline finds every degree of expression up to one in which it prevails at all stages of growth, including the adult.

1947 A. M. Davies Introd. Palaeontol. (ed. 2) iv. 139 In some cases..the youthful whorl-shape foreshadows the adult whorl-shape of forms that come later in time... This reverse sequence to that of palingenesis is termed proterogenesis or cænogenesis, and has been observed in other animal phyla, particularly in the Graptolites.

1966 D. D. Davis & R. Zangerl tr. W. Hennig Phylogenetic Systematics iii. 228 The theory of the ‘early ontogenetic origin of types’ assumes a special place in discussions of the origin of higher categories or new types. Equivalent or nearly equivalent are the concepts of ‘proterogenesis’ (Schindewolf), paedomorphism (Garstang), and—as Wettstein 1942 emphasizes—the designations diametagenesis.., fetalization.., and neomorphosis.

1992 Sci. Amer. July 93/3 Schindewolf's subtle theory contained a central element of insensible change in a process that he called proterogenesis (gradual seepage of juvenile traits into adult stages).