Kwararrun da ke kashewa

Kwararrun kyarkeci (Aenocyon dirus[1] /iːˈnɒkaɪ . ɒn ˈdaɪrəs/ i) wani nau'in kare ne wanda ya kasance asalin Amurka a lokacin Late Pleistocene da Early Holocene (shekaru 125,000-10,000 da suka gabata). An sanya sunan jinsin a cikin 1858, shekaru hudu bayan an sami samfurin farko. An gabatar da nau'o'i biyu, Aenocyon dirus guildayi da Aenocyon dirus dirus, amma kwanan nan an yi la'akari da wannan aikin da ake tambaya. An samo tarin burbushin burbushinsa mafi girma daga Rancho La Brea Tar Pits a Los Angeles.

An gano ragowar kyarkeci a fadin wurare masu yawa ciki har da filayen, wuraren ciyawa, da wasu yankunan tsaunuka na Arewacin Amurka da kuma busassun Savanna na Kudancin Amurka. Shafukan suna cikin tsawo daga matakin teku zuwa mita 2,255 (7,400 . Ba a sami burbushin wolf da yawa a arewacin latitude 42 ° N; akwai rubuce-rubuce guda biyar da ba a tabbatar da su ba sama da wannan latitude. Wannan ƙuntatawa na kewayon ana zaton saboda zafin jiki, ganima, ko iyakancewar mazaunin da aka ɗora ta hanyar kusanci da kankara na Laurentide da Cordilleran waɗanda suka wanzu a lokacin.

Kyakkyawan kyarkeci ya kasance daidai da girman mafi girman nau'ikan zamani na gashin gashi ('Canis lupus): kyarkecin Yukon da kyarkejin arewa maso yamma. A. d. guildayi   ya auna a matsakaita 60 kilogram (132 kuma A. d' dirus ya kasance a matsakaita 68 kg (150 lb) kg (150 lb). Kwancensa da hakora sun yi daidai da na C. lupus , amma hakora sun fi girma tare da ikon aski mafi girma, kuma ƙarfin cinyewa a haƙoran canine ya fi ƙarfin kowane nau'in Canis da aka sani. Wadannan halaye ana zaton su ne daidaitawa don cin nama a kan Late Pleistocene Megaherbivores; a Arewacin Amurka, an ba da shawarar ganimar ta sun haɗa da dawakai na yamma, dwarf pronghorn, peccary mai kaifi, sloths na ƙasa, tsohuwar bison, da raƙuma. Kwararrun karnuka sun rayu kwanan nan kamar Shekaru 10,000 da suka gabata, bisa ga ragowar kwanan wata. Ya ƙare a lokacin taron Quaternary, ya ɓace tare da manyan nau'ikan ganima; an ba da shawarar dogaro da Megaherbivores a matsayin dalilin ya ƙare, tare da canjin yanayi da gasa tare da wasu nau'ikan, ko haɗuwa da waɗannan abubuwan.

Tarihin lissafi

Daga shekarun 1850, ana samun burbushin burbushin manyan kyarketai a Amurka, kuma ba a bayyana nan da nan cewa waɗannan duk sun kasance na jinsin daya ba. An samo samfurin farko na abin da daga baya zai zama mai alaƙa da Aenocyon dirus a tsakiyar 1854 a cikin gadon Kogin Ohio kusa da Evansville, Indiana. Masanin ilimin ƙasa Joseph Granville Norwood ne ya samo burbushin jaw tare da hakoran kumfa daga mai tarawa na Evansville, Francis A. Linck. Masanin ilimin halittu Joseph Leidy ya ƙaddara cewa samfurin yana wakiltar nau'in kyarkeci kuma ya ba da rahoton shi a ƙarƙashin sunan 'Canis primaevus . An adana wasiƙun Norwood zuwa Leidy tare da nau'in samfurin (na farko na jinsin da ke da bayanin rubuce-rubuce) a Kwalejin Kimiyya ta Philadelphia. A shekara ta 1857, yayin da yake bincika kwarin Kogin Niobrara a Nebraska, Leidy ya sami kashin baya na jinsin Canis wanda ya bayar da rahoto a shekara mai zuwa a ƙarƙashin sunan C. dirus . Sunan 'C. primaevus   (Leidy 1854) daga baya aka sake masa suna Canis indianensis (Leidy 1869) lokacin da Leidy ya gano cewa sunan C. primaевus a baya masanin halitta na Burtaniya Brian Houghton Hodgson ya yi amfani da shi don dhole.

Nuni a Gidan Tarihi na 404 mummunan kwanyar wolf da aka samu a cikin La Brea Tar Pits

A cikin 1876, masanin ilimin dabbobi Joel Asaph Allen ya gano ragowar ''Canis Mississippiensis (Allen 1876) kuma ya haɗa waɗannan da '''''''C. dirus       (Leidy 1858) da Canis indianensis (Leidy 1869). Kamar yadda aka sami kadan daga cikin waɗannan samfurori uku, Allen ya yi tunanin ya fi kyau a bar kowane samfurin da aka jera a ƙarƙashin sunansa na wucin gadi har sai an sami ƙarin kayan don bayyana dangantakarsu. A cikin 1908 masanin burbushin halittu John Campbell Merriam ya fara dawo da raguwar kasusuwa da yawa na babban kyarkeci daga ramukan tar na Rancho La Brea. A shekara ta 1912 ya sami kwarangwal cikakke don ya iya gane waɗannan da samfuran da aka samu a baya a ƙarƙashin sunan C. dirus (Leidy 1858). Saboda ka'idojin nomenclature sun tsara cewa sunan jinsin ya kamata ya zama sunan da ya fi tsufa da aka taɓa amfani da shi, Merriam don haka ya zaɓi sunan samfurin Leidy na 1858, C. dirus. A cikin 1915 masanin burbushin halittu Edward Troxell ya nuna yarjejeniyarsa da Merriam lokacin da ya ayyana C. indianensis  daidai da C. dirus . A cikin 1918, bayan nazarin waɗannan burbushin, Merriam ya ba da shawarar karfafa sunayensu a ƙarƙashin jinsin Aenocyon' (daga ainos, 'mummunan' da cyon, 'karen') don zama Aenocyen dirus, amma a wannan lokacin ba kowa ya yarda da wannan kyarkeci da aka sanya shi a cikin sabon jinsin da ya bambanta da jinsin Canis. Canis ayersi (Sellards 1916) da 'Aenocyon dirus' (Merriam 1918) an gane su a matsayin ma'anar C. dirus ta hanyar masanin burbushin halittu Ernest Lundelius a cikin 1972. Dukkanin harajin da ke sama an ayyana su daidai da C. dirus a cikin 1979, a cewar masanin burbushin halittu Ronald M. Nowak . Koyaya, Hill et al. (2025) sun bincika tarihin lissafi na C. Mississippiensis kuma kai tsaye sun kwatanta ƙasusuwan da aka danganta ga C. miss Mississippiensis tare da na Pleistocene gray wolf (Canis lupus) da mummunan wolf (Aenocyon dirus), sun kai ga ƙarshe cewa C. mississipíensis mai yiwuwa daidai yake da C. lupus. 

A cikin shekara ta 1984, wani binciken da masanin burbushin halittu na Finland Björn Kurtén ya yi ya gane bambancin ƙasa a cikin yawan mutanen da ke cikin kyarkeci kuma ya ba da shawarar nau'o'i biyu: Canis dirus guildayi (wanda Kurtén ya sanya masa suna don girmama masanin burus na Amurka John E. Guilday) don samfurori daga California da Mexico waɗanda suka nuna gajerun gajere da dogon hakora, da Canis dirusi don samfurorin gabashin Arewacin Amurka Continental Divide wanda ya nuna dogon hakora. Kurtén ya sanya Maƙarƙashiya da aka samo a cikin Hermit's Cave, New Mexico, a matsayin wakiltar nau'in C. d. dirus. A cikin 2019, masanan burbushin halittu Damián Ruiz-Ramoni da Marisol Montellano-Ballesteros a Jami'ar National Autonomous ta Mexico sun yi tambaya game da wannan takamaiman aikin, waɗanda ba su iya samun bambanci mai mahimmanci tsakanin samfuran da aka sanya wa kowane nau'in da aka gabatar ba.

A cikin 2021, binciken DNA ya gano mummunan kyarkeci ya zama zuriya mai banbanci sosai idan aka kwatanta da karnuka masu kama da kyarkeci, kuma wannan binciken ya dace da rarrabawar da aka gabatar a baya na mummunan kyarketai a matsayin nau'in Aenocyon (Girkanci na dā: "mummunan kyarke") kamar yadda Merriam ya gabatar a cikin 1918.

Iyalin canid sun fara bayyana a cikin burbushin burbushin Arewacin Amurka kusan shekaru miliyan 40 da suka gabata, kuma dangin canine Canina" id="mwASY" rel="mw:WikiLink" title="Caninae">Caninae kimanin shekaru miliyan 32 da suka gabata. Daga Caninae, kakannin Vulpini mai kama da kyanwa da Canini mai kama le kare sun rabu da kimanin shekaru miliyan 9 da suka gabata. Canini sun fara wakiltar Eucyon, kuma galibi ta hanyar Coyote-kamar Eucyon davisi wanda ya bazu ko'ina a Arewacin Amurka. Daga Canini Cerdocyonina ya bunkasa shekaru miliyan 6-5 da suka gabata, a yau wakilan zuriyar canid da ke cikin asalin Kudancin Amurka. Abubuwan burbushin 'yar'uwarta, mai kama da kyarkeci, sun fara bayyana shekaru miliyan 5 da suka gabata; duk da haka, an yi imanin cewa sun samo asali ne tun shekaru miliyan 9 da suka gabata. Kimanin shekaru miliyan 7 da suka gabata, karnuka sun fadada zuwa Eurasia da Afirka, tare da Eucyon wanda ya haifar da mambobi na farko na jinsin Canis" id="mwAUc" rel="mw:WikiLink" title="Canis">Canis a Turai. Kimanin shekaru miliyan 4-3 da suka gabata C. chihliensis , memba na farko mai girman kyarkeci na Canis, ya tashi a kasar Sin kuma ya haskaka cikin wasu kyarkeyi masu kama da kyarkewa a duk faɗin Eurasia da Afirka. Membobin jinsin Canis daga baya sun fadada zuwa Arewacin Amurka.

Kyakkyawan kyarkeci ya samo asali ne a Arewacin Amurka. Koyaya, ana muhawara game da asalin kakanninta, tare da ra'ayoyi biyu masu gasa: Ka'idar farko ta dogara ne akan yanayin burbushin halittu, wanda ke nuna cewa fadada jinsin Canis daga Eurasia ya haifar da mummunan kyarkeci. Ka'idar ta biyu ta dogara ne akan shaidar DNA, wanda ke nuna cewa mummunan kyarkeci ya fito ne daga zuriyar kakannin da ta samo asali a Amurka kuma ta rabu da jinsin Canis.

Shaidar yanayin halittu

Samfuri:CladogramShaidar morphological da ta danganci burbushin burbushin halittu ta nuna fadada jinsin Canis daga Eurasia ya haifar da mummunan kyarkeci.

A shekara ta 1974 Robert A. Martin ya ba da shawarar cewa babban kyarkeci na Arewacin Amurka C. armbrusteri  (kwarkeci na Armbruster) shine 'C. lupus    . Nowak, Kurtén, da Annalisa Berta sun ba da shawarar cewa 'C. dirus    ba a samo shi daga C. lupus ba. A shekara ta 1987, wani sabon ra'ayi ya ba da shawarar cewa yawan dabbobi masu shayarwa na iya haifar da wani nau'i mai girma da ake kira hypermorph a lokacin da abinci ya zama mai yawa, amma lokacin da abinci daga baya ya zama ƙarancin hypermorph zai iya daidaitawa da ƙaramin nau'i ko ya ƙare. Wannan ra'ayi na iya bayyana girman jiki da aka samu a yawancin dabbobi masu shayarwa na Late Pleistocene idan aka kwatanta da takwarorinsu na zamani. Dukkanin halaka da jinsin - tsari ne wanda sabon nau'in ya rabu da tsofaffi - na iya faruwa tare a lokutan matsanancin yanayi. Gloria D. Goulet ta yarda da Martin, ta ci gaba da bayar da shawarar cewa wannan ra'ayi na iya bayyana bayyanar kwatsam na C. dirus a Arewacin Amurka kuma, yin hukunci daga kamanceceniya a cikin siffofin kwanyarsu, cewa C. lupus ya haifar da C. diris hypermorph saboda yawan wasan, yanayi mai ɗorewa, da manyan masu fafatawa. –  –