Maximum clade credibility tree (BEAST) with constrained nodes labelled according to Table2. Tectonic maps were redrawn from Blakey . CPE indicates the Carnian Pluvial Event . Calibrated nodes are numbered X and 1–12 as in Table 1 but Y, crown Archosauria, is not shown. For results from the MrBayes analysis, including posterior probabilities of separate nodes, see Additional file 5.