Fig. 5 in On the affinities of Tetraceratops insignis, an Early Permian synapsid

Fig. 5. Time−calibrated tree displaying the relationship between Haptodus, Dimetrodon, Tetraceratops, and 20 other therapsids. The putative position of Eutheriododontia (a taxon that includes Therocephalia and Cynodontia, the latter including Mammalia) was added after the analysis, in the position suggested (for Cynodontia) by Liu et al. (2009). The bootstrap and Bremer support values are also included. The branch lengths are approximate but reflect geological time.