Editing Hummingbird (section)

== Taxonomy and systematics ==
{{Further|List of hummingbird species}}

The family Trochilidae was introduced in 1825 by Irish zoologist [[Nicholas Aylward Vigors]] with ''[[Trochilus]]'' as the [[type genus]].<ref>{{Cite journal |last=Vigors |first=Nicholas Aylward |author-link=Nicholas Aylward Vigors |year=1825 |title=Observations on the natural affinities that connect the orders and families of birds |url=https://www.biodiversitylibrary.org/page/752841 |journal=Transactions of the Linnean Society of London |volume=14 |issue=3 |pages=395–517 [463] |doi=10.1111/j.1095-8339.1823.tb00098.x}}</ref><ref>{{Cite book |last=Bock |first=Walter J. |url=http://digitallibrary.amnh.org/handle/2246/830 |title=History and Nomenclature of Avian Family-Group Names |publisher=American Museum of Natural History |year=1994 |series=Bulletin of the American Museum of Natural History |volume=222 |location=New York |pages=143, 264 |hdl=2246/830}}<!--Linked page allows download of the 48MB pdf--></ref> In traditional [[Taxonomy (biology)|taxonomy]], hummingbirds are placed in the order [[Apodiformes]], which also contains the [[Swift (bird)|swift]]s, but some taxonomists have separated them into their own order, the Trochiliformes.<ref name=S&A1990>{{cite book |last1=Sibley |first1=Charles Gald |last2=Ahlquist |first2=Jon Edward |year=1990 |title=Phylogeny and classification of birds |publisher=Yale University Press |location=New Haven, Conn.}}</ref> 

Hummingbird [[Bird_wing#Anatomy|wing bones]] are hollow and fragile, making [[fossil]]ization difficult and leaving their evolutionary history poorly documented. Though scientists theorize that hummingbirds originated in South America, where species diversity is greatest, possible ancestors of extant hummingbirds may have lived in parts of Europe and what is southern [[Russia]] today.<ref name="mayr2005">{{Cite journal |last=Mayr |first=Gerald |date=March 2005 |title=Fossil hummingbirds of the Old World |url=http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/hummingbird_biologist.pdf |url-status=dead |journal=Biologist |volume=52 |issue=1 |pages=12–16 |archive-url=https://web.archive.org/web/20110927045239/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/hummingbird_biologist.pdf |archive-date=2011-09-27 |access-date=2009-12-14}}</ref>

As of 2023, 366 hummingbird species have been identified.<ref name=IOC/> They have been traditionally divided into two [[Subfamily|subfamilies]]: the [[hermit (hummingbird)|hermits]] (Phaethornithinae) and the typical hummingbirds (Trochilinae, including all the other species). Molecular phylogenetic studies have shown, though, that the hermits are [[sister taxon|sister]] to the topazes and jacobins, making the former definition of Trochilinae not [[monophyletic]]. The hummingbirds form nine major [[clade]]s: the [[Florisuginae|topazes and jacobins]], the [[Hermit (hummingbird)|hermits]], the [[Polytminae|mangoes]], the [[Lesbiini|coquettes]], the [[Heliantheini|brilliants]], the [[giant hummingbird]] (''Patagona gigas''), the [[Lampornithini|mountaingem]]s, the [[Mellisugini|bees]], and the [[Trochilini|emeralds]].<ref name=mcguire2014/> The topazes and jacobins combined have the oldest split with the rest of the hummingbirds. The hummingbird family has the third-greatest number of species of any bird family (after the [[tyrant flycatcher]]s and the [[tanager]]s).<ref name=mcguire2014/><ref name="IOC"/>

Fossil hummingbirds are known from the [[Pleistocene]] of [[Brazil]] and the [[Bahamas]], but neither has yet been scientifically described, and fossils and subfossils of a few extant species are known. Until recently, older fossils had not been securely identifiable as those of hummingbirds.

In 2004, [[Gerald Mayr]] identified two 30-million-year-old hummingbird fossils. The fossils of this primitive hummingbird species, named ''[[Eurotrochilus]] inexpectatus'' ("unexpected European hummingbird"), had been sitting in a [[museum]] drawer in [[Stuttgart]]; they had been unearthed in a clay pit at [[Wiesloch]]–Frauenweiler, south of [[Heidelberg]], [[Germany]], and, because hummingbirds were assumed to have never occurred outside the Americas, were not recognized to be hummingbirds until Mayr took a closer look at them.<ref name=mayr2005/><ref name="Mayr2004">{{Cite journal |last=Mayr |first=Gerald |date=2004 |title=Old World fossil record of modern-type hummingbirds |journal=Science |volume=304 |issue=5672 |pages=861–864 |bibcode=2004Sci...304..861M |doi=10.1126/science.1096856 |pmid=15131303 |s2cid=6845608}}</ref>

Fossils of birds not clearly assignable to either hummingbirds or a related extinct family, the Jungornithidae, have been found at the [[Messel pit]] and in the [[Caucasus]], dating from 35 to 40 million years ago; this indicates that the split between these two lineages indeed occurred around that time. The areas where these early fossils have been found had a climate quite similar to that of the northern Caribbean or southernmost [[China]] during that time. The biggest remaining mystery at present is what happened to hummingbirds in the roughly 25 million years between the primitive ''Eurotrochilus'' and the modern fossils. The astounding morphological [[adaptation]]s, the decrease in size, and the dispersal to the Americas and extinction in Eurasia all occurred during this timespan. [[DNA–DNA hybridization]] results suggest that the main radiation of South American hummingbirds took place at least partly in the [[Miocene]], some 12 to 13 million years ago, during the uplifting of the northern [[Andes]].<ref name="Bleiweiss et al.">{{Cite journal |last1=Bleiweiss |first1=Robert |last2=Kirsch |first2=John A. W. |last3=Matheus |first3=Juan Carlos |year=1999 |title=DNA-DNA hybridization evidence for subfamily structure among hummingbirds |url=http://sora.unm.edu/sites/default/files/journals/auk/v111n01/p0008-p0019.pdf |journal=[[Auk (journal)|Auk]] |volume=111 |issue=1 |pages=8–19 |doi=10.2307/4088500 |jstor=4088500 |access-date=1 April 2013 |archive-date=25 July 2021 |archive-url=https://web.archive.org/web/20210725122234/https://sora.unm.edu/sites/default/files/journals/auk/v111n01/p0008-p0019.pdf |url-status=dead }}</ref>

In 2013, a 50-million-year-old bird fossil unearthed in [[Wyoming]] was found to be a predecessor to hummingbirds and swifts before the groups diverged.<ref>{{Cite journal |last1=Ksepka |first1=Daniel T. |last2=Clarke |first2=Julia A. |last3=Nesbitt |first3=Sterling J. |last4=Kulp |first4=Felicia B. |last5=Grande |first5=Lance |year=2013 |title=Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes) |journal=Proceedings of the Royal Society B |volume=280 |issue=1761 |page=1761 |doi=10.1098/rspb.2013.0580 |pmc=3652446 |pmid=23760643}}</ref>