The trogons and quetzals are birds in the order Trogoniformes which contains only one family, the Trogonidae. The family Trogonidae contains 46 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 or be closely related to mousebirds and owls. The word trogon is Greek for "nibbling" and refers to the fact that these birds gnaw holes in trees to make their nests. Trogons are residents of tropical forests worldwide. The greatest diversity is in the Neotropics, where four genera, containing 24 species, occur. The genus Apaloderma contains the three African species. The genera Harpactes and Apalharpactes, containing twelve species, are found in southeast Asia. They feed on insects and fruit, and their broad bills and weak legs reflect their diet and arboreal habits. Although their flight is fast, they are reluctant to fly any distance. Trogons are generally not migratory, although some species undertake partial local movements. Trogons have soft, often colourful, feathers with distinctive male and female plumage. They are the only type of animal with a heterodactyl toe arrangement. They nest in holes dug into trees or termite nests, laying 2–4 white or pastel-coloured eggs. Evolution and taxonomy The position of the trogons within the class Aves has been a long-standing mystery. 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; to 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 notwithstanding the current richness of the family, which is more diverse in the Neotropical New World. DNA evidence seemed