Ithimba labacwaningi eliholwa uprofesa wase-Texas A&M University linqume ukuthi i-Manis bone projectile point iyisikhali esidala kunazo zonke esake satholwa emazweni aseMelika, esahlehlela emuva eminyakeni eyi-13,900.
UDkt. Michael Waters, uprofesa ovelele we-anthropology kanye nenhloko ye-Texas A&M's Center for the Study of First Americans, uhole ithimba elishicilele imiphumela yalo ku-Science Advances kuleli sonto.
Abacwaningi babheke izingcezu zamathambo ezihloliwe eziqukethwe ethanjeni le-mastodon lembambo elatholwa uCarl Gustafson ngesikhathi kumbiwa endaweni yaseManis esifundazweni saseWashington kusukela ngo-1977 kuya ku-1979.
Amanzi kanye nozakwabo bahlonze zonke izingcezu zamathambo besebenzisa i-CT scan kanye nesofthiwe ye-3D ukufakazela ukuthi kwakuyiphuzu lesikhali-i-projectile eyenziwe ngethambo likaMastodon, izihlobo zangaphambili zezindlovu.
“Sazihlukanisa izingcezu zamathambo, saziphrinta, sazihlanganisa,” kusho uWaters. “Lokhu kukhombisa ngokusobala ukuthi leli bekuyiphuzu lethambo. Leli yiphuzu elidala kunawo wonke lamathambo eMelika futhi limelela ubufakazi obudala obuqondile bokuzingela i-mastodon emazweni aseMelika.”
U-Waters uthe eminyakeni engu-13,900 ubudala, iphuzu laseManis lidala ngeminyaka engu-900 kunamaphuzu e-projectile atholakala ehlotshaniswa nabantu baseClovis, amathuluzi abo amatshe abuye wawafunda. Ukuthandana kusukela eminyakeni engu-13,050 kuya ku-12,750 edlule, amaphuzu omkhonto kaClovis atholakale eTexas nakwezinye izingosi ezimbalwa ezweni lonke.
“Okubalulekile ngeManis wukuthi iyithuluzi lokuqala neliwukuphela kwethambo elidala kunoClovis. Kwenye indawo eyandulela i-Clovis, kutholakala amathuluzi amatshe kuphela,” kusho uWaters. "Lokhu kukhombisa ukuthi amaMelika Okuqala enza futhi asebenzisa izikhali zamathambo kanye nezinye izinhlobo zamathuluzi amathambo."
Uthe okuwukuphela kwesizathu esenza ukuthi isampula ye-Manis ilondolozwe yingoba umzingeli wageja, futhi i-projectile yabhajwa kubambo lwe-mastodon.
"Sibonisa ukuthi ithambo elisetshenziselwe ukwenza iphuzu libonakale livela ethanjeni lomlenze lenye i-mastodon futhi lakhiwe ngamabomu libe yifomu le-projectile point," kusho u-Waters. “Umkhonto onephuzu lethambo wawujikijelwa kumastodon. Yangena esikhumbeni nasesicubuni yagcina ihlangene nombambo. Inhloso yomzingeli kwakuwukungena phakathi kwezimbambo futhi aphazamise ukusebenza kwamaphaphu, kodwa umzingeli wageja futhi washaya ubambo.”
Amanzi afunde ithambo lombambo ngaphambilini, ethula okutholakele ephepheni lika-2011 elanyatheliswa kuyi-Science, lapho ukuphola kwe-radiocarbon kunqume ubudala bethambo kanye nocwaningo lofuzo lwezicucu zamathambo zathola ukuthi ziyi-mastodon.
"Ocwaningweni lwethu olusha, sizimisele ukuhlukanisa izingcezu zamathambo sisebenzisa izithombe ze-CT nesoftware ye-3D," esho. “Sikwazile ukwenza izithombe ze-3D zocezu ngalunye futhi siziphrinte esikalini esiphindwe kasithupha. Sibe sesihlanganisa izingcezu ukuze sibonise ukuthi isifanekiso sasibukeka kanjani ngaphambi kokuba singene futhi siqhekeke ezimbanjeni.”
Akukuningi okwaziwayo ngabantu abasebenzisa umkhonto waseManis ngaphandle kokuthi babengaboMdabu bokuqala ukungena emazweni aseMelika. UWaters uthe indawo yaseManis nabanye banikeza abavubukuli ukuqonda okuthile.
"Kubukeka sengathi abantu bokuqala abeza emazweni aseMelika bafika ngesikebhe," esho. “Bathatha umzila osogwini ogudla iNyakatho yePacific bathuthela eningizimu. Ekugcineni badlula eqhweni elalimboze iCanada futhi bawela ePacific Northwest.
“Kuyajabulisa ukuqaphela ukuthi e-Idaho kunesiza se-Coopers Ferry esineminyaka engu-16,000 ubudala, futhi e-Oregon kuyindawo eseneminyaka eyi-14,100 yePaisley Caves. Futhi lapha sibika ngendawo yaseManis eneminyaka eyi-13,900. Ngakho kubonakala kuneqoqo lezindawo zakuqala engxenyeni eseNyakatho-ntshonalanga ye-United States ezisukela eminyakeni eyi-16,000 kuya kweyi-14,000 edlule ezandulela uClovis. Lezi zingosi cishe zimelela abantu bokuqala nezizukulwane zabo ezangena emazweni aseMelika ekupheleni kwe-Ice Age yokugcina.”
