Phylogenetic definitions for Caprimulgimorphae (Aves) and major constituent clades under the International Code of Phylogenetic Nomenclature

Phylogenetic nomenclature, a system of taxonomic nomenclature in which taxon names are defined based on phylogenetic relationships, has been widely adopted in recent decades, particularly by vertebrate palaeontologists. However, formal regulation of this taxonomic system had been non-existent until the recent implementation of the International Code of Phylogenetic Nomenclature (PhyloCode). To fulfil the requirements of the PhyloCode, we explicitly establish phylogenetic definitions that we recommended in a recent phylogenetic study on the avian taxon Caprimulgimorphae (which includes nightjars, potoos, frogmouths, swifts, hummingbirds, and others) and many of its major constituent subclades. Two new names are coined: Sedentaves (for the smallest crown clade uniting Steatornis and Nyctibiidae) and Letornithes (for the smallest crown clade uniting Podargidae and Daedalornithes). We also briefly review the fossil record and diagnostic morphological apomorphies of caprimulgimorph clades for which relevant information is available.