thumb|Male masked trogon<br />Trogon personatus temperatus

The trogons and quetzals are birds in the order Trogoniformes which contains only one family, the Trogonidae. The family Trogonidae contains 49 species in seven genera. The fossil record of the trogons dates back 49 million years to the Early Eocene. They might constitute a member of the basal radiation of the order Coraciiformes and order Passeriformes A variety of relations have been suggested, including the parrots, cuckoos, toucans, jacamars and puffbirds, rollers, owls and nightjars. More recent morphological and molecular evidence has suggested a relationship with the Coliiformes. The unique arrangement of the toes on the foot (see morphology and flight) has led many to consider the trogons to have no close relatives; this would place them in their own order, possibly with the similarly atypical mousebirds as their closest relatives.

The earliest formally described fossil specimen is a cranium from the Fur Formation Lower Eocene in Denmark (54 mya). Other trogoniform fossils have been found in the Messel pit deposits from the mid-Eocene in Germany (49 mya), and in Oligocene and Miocene deposits from Switzerland and France respectively. The oldest New World fossil of a trogon is from the comparatively recent Pleistocene (less than 2.588 mya).

The family had been thought to have an Old World origin show that the DNA evidence gives contradictory results concerning the basal phylogenetic relationships; so it is currently unknown if all extant trogons are descended from an African ancestor, an American ancestor or neither.

The trogons are split into three subfamilies, each reflecting one of these splits. Apalodermatinae is the African subfamily and contains a single genus, Apaloderma. Harpactinae is the Asian subfamily and contains two genera, Harpactes and Apalharpactes. Apalharpactes, consisting of two species in Java and Sumatra, has only recently been accepted as a separate genus from Harpactes.

Trogons are cavity nesters. Nests are dug into rotting wood or termite nests,

  • Trogon videos on the Internet Bird Collection
  • Tree of Life: Trogonidae