Body Size Reductions in Nonmammalian Eutheriodont Therapsids (Synapsida) during the End-Permian Mass Extinction
Figure 7
Ancestral state reconstructions for basal skull length in Permian and Triassic therocephalians.
Colored horizontal bars indicate ranges of tip taxa spanning more than one stratigraphic bin. Note that significant decreases in mean sizes of major subgroups across the Permian-Triassic boundary (dashed line) were associated with the loss of large-bodied taxa and the survival of pre-existing small-bodied taxa or clades. Abbreviations: CiAZ,Cistecephalus Assemblage Zone; CynAZ,Cynognathus Assemblage Zone; DAZ,Dicynodon Assemblage Zone; LAZ,Lystrosaurus Assemblage Zone.