Editing Pika (section)

===Extinct species===
Many fossil forms of ''Ochotona'' are described in the literature, from the [[Miocene]] epoch to the early [[Holocene]] ([[Extinction|extinct]] species) and present (16.4-0 [[Megaannum#SI prefix multipliers|Ma]]<ref name="Ge13" />). They lived in Europe, Asia, and North America.Some species listed below are common for Eurasia and North America (''O. gromovi'', ''O. tologoica'', ''O. zazhigini'', and probably ''O. whartoni'').

* Eurasia
** large forms
*** †''[[Ochotona chowmincheni]]'' ([[China]]: [[Baode]] area, late Miocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona gromovi]]'' ([[Asia]], [[Pliocene]], see also North America)<ref name="Erbajeva11" />
*** †''[[Ochotona gudrunae]]'' (China: [[Shanxi]], early [[Pleistocene]])<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona guizhongensis]]'' ([[Tibet]], late Miocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Cai89" />
*** †''[[Ochotona lagreli]]'' (China: [[Inner Mongolia]], late Miocene to late Pliocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" /><ref name="Cai89" />
*** †''[[Ochotona magna]]'' (China, early Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
*** †''[[Ochotona tologoica]]'' ([[Transbaikal]]ia, Pliocene, see also North America)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
*** †''[[Ochotona transcaucasica]]'' ([[Transcaucasia]]: eastern [[Georgia (country)|Georgia]] and [[Azerbaijan]], Transbaikal and probably southern Europe, early to late Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona ursui]]'' ([[Romania]], Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona zasuchini]]'' (Transbaikalia, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
*** †''[[Ochotona zazhigini]]'' (Asia, Pliocene, see also North America)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona zhangi]]'' (China, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
**medium-sized forms
*** †''[[Ochotona agadjianiani]]'' (Asia, Pliocene)<ref name="Erbajeva11" />
*** †''[[Ochotona antiqua]]'' ([[Moldavia]], [[Ukraine]], and the [[Russia]]n Plain, [[Caucasus]], and probably [[Rhodes]], late Miocene to Pliocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona azerica]]'' (Transcaucasia: Azerbaijan,<ref name="Cermak06" /> middle Pliocene)<ref name="Ge13" /><ref name="Erbajeva05" />
*** †''[[Ochotona lingtaica]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona dodogolica]]'' (Asia: western Transbaikalia, Pleistocene)<ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona nihewanica]]'' (China: [[Hebei]], early Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" /><ref name="Erbajeva03" />
*** †''[[Ochotona plicodenta]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona polonica]]'' (Europe: [[Poland]], [[Germany]], [[France]], Pliocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
** small-sized forms
*** †''[[Ochotona bazarovi]]'' (Asia, upper Pliocene)<ref name="Ge13" /><ref name="Erbajeva05" /><ref name="Erbajeva03" />
*** †''[[Ochotona dehmi]]'' (Germany: [[Schernfeld]], Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona filippovi]]'' ([[Siberia]], Pleistocene)<ref name="Ge13" /><ref name="Erbajeva03" />
*** †''[[Ochotona gracilis]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona horaceki]]'' ([[Slovakia]]: [[Honce]], Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona minor]]'' (China, late Miocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Cai89" />
*** †''[[Ochotona sibirica]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona valerotae]]'' ([[France]]: Valerots site, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona youngi]]'' (Asia, Pliocene)<ref name="Erbajeva11" /><br />and others.<ref name="Ge13" /><ref name="Erbajeva11" />
** other examples
*** †''[[Ochotona agadzhaniani]]'' (Transcaucasia: [[Armenia]], Pliocene)<ref name="Ge13" />
*** †''[[Ochotona alaica]]'' (Asia: [[Kyrgyzstan]], Pleistocene)<ref name="Ge13" />
*** †[[Ochotona eximia|''Ochotona'' (''Proochotona'') ''eximia'']] ([[Moldova]], Ukraine, Russia, [[Kazakhstan]], Miocene to Pliocene)<ref name="Ge13" />
*** †[[Ochotona gigas|''Ochotona'' (''Proochotona'') ''gigas'']] (Ukraine, Pliocene)<ref name="Ge13" />
*** †''[[Ochotona gureevi]]'' (Transbaikalia, middle Pliocene)<ref name="Ge13" /><ref name="Erbajeva05" />
*** †''[[Ochotona hengduanshanensis]]'' (China, Pleistocene)<ref name="Ge13" />
*** †''[[Ochotona intermedia]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †[[Ochotona kalfaense|''Ochotona'' (''Proochotona'') ''kalfaense'']] (Europe: [[Moldova]], Miocene)<ref name="Ge13" />
*** †[[Ochotona kirgisica|''Ochotona'' (''Proochotona'') ''kirgisica'']] (Asia: Kyrgyzstan, Pliocene)<ref name="Ge13" />
*** †''[[Ochotona kormosi]]'' ([[Hungary]], Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" />
*** †[[Ochotona kurdjukovi|''Ochotona'' (''Proochotona'') ''kurdjukovi'']] (Asia: Kyrgyzstan, Pliocene)<ref name="Ge13" />
*** †''[[Ochotona largerli]]'' (Georgia, Pleistocene)<ref name="Ge13" />
*** †''[[Ochotona lazari]]'' (Ukraine, Pleistocene)<ref name="Ge13" />
*** †''[[Ochotona mediterranensis]]'' ([[Turkey]], Pliocene)<ref name="Ge13" />
*** †''[[Ochotona ozansoyi]]'' (Turkey, Miocene)<ref name="Ge13" />
*** †''[[Ochotona pseudopusilla]]'' (Ukraine and Russian Plain, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona spelaeus]]'' (Ukraine, late Pleistocene)<ref name="Ge13" /><ref name="Rekovets" />
*** †''[[Ochotona tedfordi]]'' (China: [[Yushe Basin]], late Miocene)<ref name="Ge13" /><ref name="Fostowicz10" />
*** †''[[Giant pika|Ochotona cf. whartoni]]'' ([[Irkutsk Oblast]] and [[Sakha Republic|Yakutia]], Pleistocene, see also North America)<ref name="Erbajeva11" />
*** †''[[Ochotona zabiensis]]'' (southern [[Poland]], early Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" />
*** †''Ochotona'' sp. ([[Greece]]: [[Maritsa]], Pliocene)<ref name="Erbajeva11" />
*** †''Ochotona'' sp. (Hungary: [[Ostramos]], Pleistocene)<ref name="Erbajeva11" />
*** †''Ochotona'' sp. (Siberia, Pleistocene)<ref name="Erbajeva11" />
*** †''Ochotona'' sp. (Yakutia, Pleistocene)<ref name="Erbajeva11" />
* North America
** †''[[Ochotona gromovi]]'' ([[United States|US]]: [[Colorado]], Pliocene, see also Eurasia)<ref name="Ge13" />
** †''[[Ochotona spanglei]]'' (US, late Miocene or early Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva03" /><ref name="Shotwell56" /><ref name="PaleoDBOspan" />{{refn|group=n|name=b|''Ochotona spanglei'' in the Paleobiology Database.<ref name="PaleoDBOspan" /><ref group=pdb name="Shotwell56" /><ref group=pdb name="Voorhies90" /><ref group=pdb name="PaleoDBOspan2" />}}
** †''[[Ochotona tologoica]]'' (US: Colorado, Pliocene, see also Eurasia)<ref name="Ge13" />
** †''Ochotona whartoni'' ([[giant pika]], US, [[Canada]], Pleistocene to early Holocene, see also Eurasia)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva03" /><ref name="GuthrieMatthews71" /><ref name="PaleoDBOwhar" />{{refn|group=n|name=c|''Ochotona whartoni'' in the Paleobiology Database.<ref name="PaleoDBOwhar" /><ref group=pdb name="Guthrie71" /><ref group=pdb name="Jopling81" /><ref group=pdb name="Harington78" /><ref group=pdb name="Harington90" /><ref group=pdb name="Storer04" /><ref group=pdb name="Tedford09" /><ref group=pdb name="PaleoDBOwhar2" />}}
** †''[[Ochotona wheatleyi]]'' (US: [[Alaska]], Pliocene, late Pleistocene)<ref name="Ge13" />
** †''[[Ochotona zazhigini]]'' (US: Colorado, Pleistocene, see also Eurasia)<ref name="Ge13" />
** extinct small pikas similar to the ''[[Steppe pika|O. pusilla]]'' group (Pleistocene)<ref name="Erbajeva11" /><ref name="Erbajeva03" />

Paleontologists have also described multiple forms of pika not referred to specific species (''Ochotona'' indet.) or not certainly identified (''O.'' [[cf.]] ''antiqua'', ''O.'' cf. ''cansus'', ''O.'' cf. ''daurica'', ''O.'' cf. ''eximia'', ''O.'' cf. ''gromovi'', ''O.'' cf. ''intermedia'', ''O.'' cf. ''koslowi'', ''O.'' cf. ''lagrelii'', ''O.'' cf. ''nihewanica''). The statuses of ''Ochotona'' (''Proochotona'') ''kirgisica'' and ''O. spelaeus'' are uncertain.<ref name="Ge13" />

The "''pusilla''" group of pikas is characterized by archaic ([[Symplesiomorphy|plesiomorphic]]) cheek teeth and small size.<ref name="Erbajeva03" />

The North American species migrated from Eurasia. They invaded the New World twice:

* ''O.  spanglei'' during the latest Miocene or early Pliocene, followed by a roughly three-million-year-long gap in the known North American pika record<ref name="Erbajeva11" />
*''O.  whartoni'' (giant pika) and small pikas via the [[Beringia|Bering Land Bridge]] during the earliest Pleistocene<ref name="Erbajeva11" />

''Ochotona'' [[cf.]] ''whartoni'' and small pikas of the ''O. pusilla'' group are also known from Siberia. The extant, [[endemic]] North American species appeared in the Pleistocene. The North American collared pika (''O. collaris'') and [[American pika]] (''O. princeps'') have been suggested to have descended from the same ancestor as the steppe pika (''O. pusilla'').<ref name="Erbajeva11" />

The range of ''Ochotona'' was larger in the past, with both extinct and extant species inhabiting Western Europe and Eastern North America, areas that are currently free of pikas. Pleistocene fossils of the extant steppe pika ''O. pusilla'' currently native to Asia have been found also in many countries of Europe from the [[United Kingdom]] to Russia and from [[Italy]] to Poland, and the Asiatic extant northern pika ''O. hyperborea'' in one location in the middle Pleistocene United States.<ref name="Ge13" />

[[File:Pika Ochotona sp. fossil distribution 2.png|thumb|center|720px|Pika ''Ochotona'' sp. fossil distribution. [[Extinction|Extinct]] pikas and ''Ochotona'' indet. are {{color|red|red}}, [[steppe pika]] ''O. pusilla'' {{color|blue|blue}}, [[northern pika]] ''O. hyperborea'' {{color|green|green}}, other [[extant taxon|extant]] pikas black.<ref name="Ge13" /><ref name="PaleoDBO" />{{refn|group=n|name=a|The coordinates of additional fossils not listed in the xls file attached to Ge and all paper<ref name="Ge13" /> were taken from the Paleobiology Database.<ref name="PaleoDBO" /><ref group=pdb name="Barnosky88" /><ref group=pdb name="Belyaeva48" /><ref group=pdb name="Bonifay73" /><ref group=pdb name="Cai87" /><ref group=pdb name="Deng11" /><ref group=pdb name="Erbaeva86" /><ref group=pdb name="Frazier97" /><ref group=pdb name="Gidley13" /><ref group=pdb name="Grady00" /><ref group=pdb name="Guilday79" /><ref group=pdb name="Harington78" /><ref group=pdb name="Harington90" /><ref group=pdb name="Janossy70" /><ref group=pdb name="Janossy86" /><ref group=pdb name="Jopling81" /><ref group=pdb name="Kurten80" /><ref group=pdb name="Mead96" /><ref group=pdb name="Qiu87" /><ref group=pdb name="Rasmussen74" /><ref group=pdb name="Sotnikova97" /><ref group=pdb name="Terzea96" /><ref group=pdb name="Winkler90" /><ref group=pdb name="PaleoDBO2" />}}]]

[[File:Fossil occurrences of leporids and ochotonids and global environmental change.png|thumb|[[Fossil]] occurrences of [[Leporidae|leporids]] and ochotonids and global environmental change ([[climate change]], [[C3 carbon fixation|C<sub>3</sub>]]/[[C4 carbon fixation|C<sub>4</sub>]] plants distribution)<ref name="Ge13" />]]

While ''Ochotona'' is the only currently living genus of Ochotonidae, extinct [[Genus|genera]] of ochotonids include  †''[[Albertona]]'', †''[[Alloptox]]'', †''[[Amphilagus]]'', †''[[Australagomys]]'', †''[[Austrolagomys]]'', †''[[Bellatona]]'', †''[[Bellatonoides]]'', †''[[Bohlinotona]]'', †''[[Cuyamalagus]]'', †''[[Desmatolagus]]'', †''[[Eurolagus]]'', †''[[Gripholagomys]]'', †''[[Gymnesicolagus]]'', †''[[Hesperolagomys]]'', †''[[Heterolagus]]'', †''[[Kenyalagomys]]'', †''[[Lagopsis (animal)|Lagopsis]]'', †''[[Marcuinomys]]'', †''[[Ochotonoides]]'', †''[[Ochotonoma]]'', †''[[Oklahomalagus]]'', †''[[Oreolagus]]'', †''[[Paludotona]]'', †''[[Piezodus]]'', †''[[Plicalagus]]'', †''[[Pliolagomys]]'', †''[[Prolagus]]'', †''[[Proochotona]]'' ([[Synonym (taxonomy)|syn.]] ''Ochotona''), †''[[Pseudobellatona]]'', †''[[Ptychoprolagus]]'', †''[[Russellagus]]'', †''[[Sinolagomys]]'', †''[[Titanomys]]'' and †''[[Tonomochota]]''.<ref name="Ge13" /><ref>{{cite journal|last1=Tiunov|first1=Mikhail P.|last2=Gusev|first2=Alexander E.|year=2021|title=A new extinct ochotonid genus from the Late Pleistocene of the Russian Far East|journal=Palaeoworld|volume=30|issue=3|pages=562–572|doi=10.1016/j.palwor.2020.08.003}}</ref> The earliest one is ''Desmatolagus'' (middle Eocene to Miocene, 42.5–14.8 Ma<ref name="Ge13" />), usually included in the Ochotonidae, sometimes in [[Leporidae]] or in neither ochotonid nor leporid stem-[[Lagomorpha|lagomorphs]].<ref name="Hordijk10" />

Ochotonids appeared in Asia between the late Eocene and the early Oligocene, and continued to develop along with increased distribution of [[C3 carbon fixation|C<sub>3</sub> grasses]] in previously forest dominated areas under the "climatic optimum" from the late Oligocene to middle Miocene. They thrived in Eurasia, North America, and even Africa. The peak of their diversity occurred during the period from the early Miocene to middle Miocene.  Most of them became extinct during the transition from the Miocene to Pliocene, which was accompanied by  an increase in diversity of the ''[[Leporidae|leporids]]''. It has been proposed that this switch between ochotonids and larger leporids was caused by expansion of [[C4 carbon fixation|C<sub>4</sub> plants]] (particularly the [[Poaceae]]) related to global cooling in the late Miocene, since extant pikas reveal a strong preference for [[C3 carbon fixation|C<sub>3</sub> plants]] ([[Asteraceae]], [[Rosaceae]], and [[Fabaceae]], many of them C<sub>3</sub>). Replacement of large areas of forests by open grassland first started probably in North America and is called sometimes "nature's green revolution".<ref name="Ge13" />