Figure 1. Cladogenetic body-size evolution via migration and speciation into environments that select for larger sizes. Note the occurrence of anagenetic size change as well. Reproduced with permission from McNamara (1990). Copyright Kenneth J. McNamara, (1990).

Figure 2. Diagrammatic illustration of the large-scale evolutionary trend from epifaunal, browsing regular echinoids, through shallow-burrowing, sand-dwelling echinoids to deeper-burrowing, mud-dwelling echinoids through the Mesozoic and Cenozoic. Persistence of ancestral ecomorphs illustrates increase in variance. Reproduced with permission from McNamara (1990). Copyright Kenneth J. McNamara, (1990).

Figure 3. Paedomorphocline of species of the brachiopods Tegulorhynchia and Notosaria, illustrating evolutionary trends through the Cenozoic in temporal narrowing of the shell, reduction in number of ribs, decrease in beak angle and increase in relative foramen size by progressive reduction in extent of growth of deltidial plates. These morphological trends are thought to have evolved along an environmental gradient of deep to shallow water. Abbreviations: PS, Pleistocene; R, Recent. Reproduced with permission from McNamara (1990). Copyright Kenneth J. McNamara, (1990).