heterodactylae

from The Century Dictionary.

• In ornithology, a group of picarian birds, distinguished from all other zygodactyl birds by having the second instead of the fourth toe reversed; the trogons, of the family Trogonidæ, considered as a superfamily.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) A group of birds including the trogons.