Phylloscopidae is a newly described family of small insectivorous birds formerly placed in the Old World warbler family. Phylloscopidae contains two genera, Phylloscopus and Seicercus, respectively containing around 55 and 11 species. The leaf warblers are a branch of "Old World warblers," one of 10 or more branches that sprouted as Families with the break-up of the Sylviidae.