Petrochelidon

Petrochelidon is a genus of birds known as cliff-nesting swallows.

==Taxonomy== The genus Petrochelidon was introduced in 1851 by the German ornithologist Jean Cabanis. He listed several species in the new genus but did not specify the type species. In 1855 the English zoologist George Gray designated the type as Hirundo melanogaster Swainson. This taxon is now treated as a subspecies of the American cliff swallow (Petrochelidon pyrrhonota melanogaster). The genus name Petrochelidon is from the Greek words petra, "rock", and khelidon, "swallow".