Figure 1.

Congruent molecular and palaeontological time scales place the origin of cichlid fishes in the Late Cretaceous–Eocene interval, substantially post-dating Gondwanan rifting. (a) Molecular phylogeny for Cichlidae calibrated using fossils belonging to non-cichlid groups (full phylogeny provided in electronic supplementary material, figures S1 and S2). (b) Bayesian point estimates and 95% CIs for the timing of cichlid origin based on the distribution of cichlid fossils and the availability of freshwater sedimentary deposits of Triassic–Recent age on Gondwanan landmasses that bear articulated fish remains. The top estimate is derived from the record of landmasses inhabited by extant cichlids, and the bottom estimate is derived from the record of all Gondwanan landmasses. The density of all Gondwanan horizons bearing articulated freshwater fish fossils is indicated by the histogram at the bottom of the figure (densities including disarticulated material are given in electronic supplementary material). Grey bars indicate total horizon density. Pink bars indicate the density of the subset of fossil fish horizons that bear cichlids. (c) Bayesian point estimates and 95% CIs for the timing of cichlid origin based on successive fossil outgroups to the clade. The two estimates reflect competing hypotheses for the earliest fossil examples of some outgroups. The top estimate is based on the oldest proposed outgroup ages and the bottom estimate is based on the youngest proposed outgroup ages. Cichlid illustrations, from top to bottom: Etroplus, Crenicichla, Astronotus, Hemichromis, Steatocranus, Altolamprologus and Tropheus. Continental arrangements based on palaeogeographic reconstructions by R. Blakey, originally presented in [7].