Fig. 1

Biogeographic history of the ratite birds (ostriches, emus, reas, etc.). a Current geographic distribution of extant and extinct ratite genera; areas in yellow (Antarctica, Europe) harbor fossil remains but no extant species. b Two alternative hypotheses to explain this disjunct distribution: recent, ocean-crossing dispersal events (left) or ancient, tectonic-isolating vicariance events (right). c A cladistic biogeographic analysis comprising three steps: (left) DNA-based phylogeny representing the relationships among ratite genera and their relatives: tinamous (adapted from Pereira and Baker 2006); (center) a taxon-area cladogram is constructed by replacing the taxon names in the phylogeny with the areas where they occur; (right) a cladistic biogeographic method (Brooks Parsimony analysis, Brooks 1990) is used to derive an “area cladogram” showing the relationships among the areas in Fig. 1a based on their shared endemic taxa. This area cladogram presumably represents the history of biotic connections between the areas of endemism for the ratite genera: tinamous (Tinamu, Eudromia), extinct moas (Dinornis, Anomalopteryx, Emeus), reas (Rhea, Pterocmemia), ostriches (Struthio), kiwis (Apteryx), cassowaries (Casuarius), and emus (Dromaius). Adapted from Sanmartín (2009). Paleomaps 0 million years (left) and 100 million years (right) adapted from ODSN (http://www.odsn.de/odsn/services/paleomap/paleomap.html)