Fig. 4

Bayesian inference of the loss of the postdentary trough among mammals (blue), based on the re-coded datasets (a–d [22]; e–f [21]). Each tree summarizes the following analyses: a, b Shuotheriidae unconstrained (allowed to group with australosphenidans); b constraining monophyly of the multicuspate haramiyidans and multituberculates; c constraining Shuotheriidae to fall outside Mammalia; d excluding cheek teeth characters; e forcing Kuehneotherium outside Mammalia; f allowing Kuehneotherium to fall freely in the phylogeny. Postdentary trough is lost twice in all the analyses except in (b) when the earliest haramiyidans (e.g Haramiyavia) are forced together with Euharamiyida and multituberculates. The analyses excluding cheek teeth characters (d) place primitive haramiyidans outside Mammalia, with euharamiyidans and multituberculates both falling on the therian stem lineage–negating any requirement for a third loss of the postdentary trough in mammals. In (d) Haramiyavia is not included but likely forms a clade with Megaconus as observed in several of these trees (not b)