Fig. 1

Hagfish phylogeny and tempo of diversification. Tip-dated Bayesian maximum clade credibility phylogeny of jawless fishes from two independent runs in BEAST 2.6.6 showing the interrelationships of the major lineages of hagfishes. Bars indicate 95% highest posterior density (HPD) intervals for divergence times at nodes. Outgroups not shown. Grey bars are at nodes supported by posterior values of 0.90 or more, clear bars are at nodes supported by posterior values of 0.89 or less. Gray columns indicate mass extinction events. Dagger (†) indicates extinct species known from the fossil record. Pie charts indicate ancestral state reconstructions of habitat for each node, where purple represents the probability of a slope component (either slope or shelf-slope) at each node and salmon indicates the probability of continental shelf habitat being ancestral. Inset includes the transition matrix from the polymorphic character ancestral reconstruction analysis (note that purple here is exclusively slope, as opposed to purple denoting slope/shelf-slope at nodes in the phylogeny). Photograph of Eptatretus stoutii is courtesy Douglas Fudge