Molecular phylogeny of Threskiornithidae (Aves: Pelecaniformes) based on nuclear and mitochondrial DNA.

The family Threskiornithidae includes 13 genera and 32 species, and it is traditionally divided into 2 subfamilies: Plataleinae and Threskiornithinae. We present a phylogenetic reconstruction to test the monophyly of currently accepted subfamilies, including 15 species from both subfamilies and 10 genera of family Threskiornithidae. Phylogenetic trees were inferred on the basis of the mitochondrial 16S rRNA gene and the nuclear intron 7 of β-fibrinogen. Threskiornithidae was recovered as a monophyletic group. Plataleinae formed a monophyletic group, but nested within Threskiornithinae, which was thus paraphyletic. Two major phylogenetic groups were identified: the 'endemic New World clade', including genera endemic to the American continent, and the 'widespread clade', comprising the remaining species. These phylogenetic groups diverged about 39-42 million years ago, i.e., before the separation of South America and Antarctica. Our results agree with an initial vicariance due to Gondwana break-up and subsequent colonization of species from the Old World to the New World.