Found only in the cloud forests of the equatorial mountains of western South America, the crested swoop (Velocipteryx coronata) is considered by most scholars to be the most primitive of the agilifugiform species.  The crested swoop and the other two species that share its genus share the short humeri and sickle-shaped wings of all the agilifugiforms, however, the birds' heavily-built skulls and bizzare feet cast doubt upon their precice phylogeny and have cast the genus Velocipteryx into its own subclade.

    In their behavior, crested swoops are similar to other agilifugiforms, in that they are high-speed acrobats, specializing in chasing and catching flying insects on the wing.  The birds occupy the highest canopy of the forest, darting about over the trees during the dawn and dusk, and then retiring to their nests within hollow trunks during the middle of the day and night.  They are not particularly vocal, but are known to give forth a nasal pswi when feeding.