Figure 6.8   Heterochronic evolution in the Triassic rhynchosaurs. The skull of adult (A) Late Triassic forms developed beyond the size and shape limits seen in earlier Triassic adult forms. Here, the juveniles (J) of the descendants resemble the ancestral adults, and this is thus an example of peramorphosis (“beyond formation”). (Based on Benton & Kirkpatrick 1989.)

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