Editing Trogon (section)

==Evolution and taxonomy==
[[Image:Dans l'ombre des dinosaures - Masillatrogon - 018.jpg|thumb|left|upright|Fossil of ''[[Masillatrogon]]'' from [[Messel]]]]
The position of the trogons within the class Aves has been a long-standing mystery.<ref name ="HBW">Collar, N.J. (2001). "Family Trogonidae (Trogons)", pp. 80–129 in del Hoyo, J.; Elliot, A. & Sargatal, J. (eds.). (2001) ''Handbook of the Birds of the World, Vol. 6 Mousebirds to Hornbills''. Lynx Edicions, Barcelona, Spain. {{ISBN|84-87334-30-X}}</ref> 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 [[mousebird]]s as their closest relatives.

The earliest formally described fossil specimen is a cranium from the [[Fur Formation]] [[Lower Eocene]] in Denmark (54 [[mya (unit)|mya]]).<ref name="Kristoffersen 2002">{{cite journal |last=Kristoffersen| first=Anette Vedding | year=2002| title=An early Paleocene Trogon (Aves: trogoniformes) from the Fur Formation, Denmark|journal=Journal of Vertebrate Paleontology|volume=22| issue=3|pages=661–666| doi=10.1671/0272-4634(2001)022[0661:AEPTAT]2.0.CO;2| s2cid=86016957 }}</ref> Other trogoniform fossils have been found in the [[Messel pit]] deposits from the mid-[[Eocene]] in Germany (49 [[mya (unit)|mya]]),<ref name="Mayr 2005">{{cite journal |last=Mayr| first=Gerald | year=2005| title=New trogons from the early Tertiary of Germany|journal=Ibis|volume=147| issue=3|pages=512–518| doi = 10.1111/j.1474-919x.2005.00421.x}}</ref> 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<ref name="Espinosa de los Monteros" /> notwithstanding the current richness of the family, which is more diverse in the Neotropical New World. DNA evidence seemed to support an African origin for the trogons, with the African genus ''[[Apaloderma]]'' seemingly basal in the family, and the other two lineages, the Asian and American, breaking off 20–36 million years ago. More recent studies<ref name="Moyle"/><ref name ="Johansson 2005"/><ref>{{Cite journal|last1=Oliveros|first1=Carl H.|last2=Andersen|first2=Michael J.|last3=Hosner|first3=Peter A.|last4=Mauck|first4=William M.|last5=Sheldon|first5=Frederick H.|last6=Cracraft|first6=Joel|last7=Moyle|first7=Robert G.|date=2020|title=Rapid Laurasian diversification of a pantropical bird family during the Oligocene–Miocene transition|journal=Ibis|language=en|volume=162|issue=1|pages=137–152|doi=10.1111/ibi.12707|issn=1474-919X|doi-access=}}</ref> 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. Aplodermatinae 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''.<ref name ="Collar 2002"/> The remaining subfamily, the Neotropical Trogoninae, contains the remaining four genera, ''Trogon'', ''Priotelus'', ''Pharomachrus'' and ''Euptilotis''.<ref name="HBW" />[[File:TrogonPlantarTendon.jpg|thumb|The tendons of the foot, showing the arrangement with a reversed second toe. The plantar tendon on the front (''flexor perforans digitorum'') splits into two sections, and enters the front toes while the hind plantar (''flexor longus hallucis'') splits and enters the hind toes.]]
The two Caribbean species of ''Priotelus'' are extremely ancient. The two quetzal genera, ''Pharomachrus'' and ''Euptilotis'' are possibly derived from the final and most numerous genus of trogons in the Neotropics, ''Trogon''. A 2008 study of the genetics of ''Trogon'' suggested the genus originated in Central America and radiated into South America after the formation of the [[Isthmus of Panama]] (as part of the [[Great American Interchange]]), thus making trogons relatively recent arrivals in South America.<ref name=Dacosta/>