Ku-paleontology, akuwona njalo amathambo aphelele ashintsha indaba yokuphila eMhlabeni . Ngezinye izikhathi, izingcezu ezimbalwa zegobolondo, ezivubukulwe cishe ngengozi ngesikhathi sohambo lwaseyunivesithi, zanele ukuphoqa ukubuyekezwa kwezikhathi zesikhathi eziphelele kanye nendlela izilwane ezafuduka ngayo phakathi kwamazwekazi ngesikhathi seNkathi yamaDinosaur.
Yilokho okwenzekile ngefosili yofudu oluneminyaka engu-89 million olutholakale eningizimu-ntshonalanga yeMontana , e-United States. Lesi sibonelo, esibizwa ngokuthi uhlobo lweBasilemys oluphelile futhi sahlolwa yithimba laseMontana State University (MSU), sibuyisela emuva irekhodi elidala kunawo wonke elaziwayo laleli qembu cishe ngeminyaka eyizigidi ezinhlanu, okwenza kube yingxenye ebalulekile yokuqonda ukufuduka kwezilwane phakathi kwe-Asia neNyakatho Melika ngesikhathi seCretaceous.
Ukutholwa okuthule okwashukumisa iwashi le-geological
Le fossil yatholakala ngo -2021 ku-Frontier Formation , uchungechunge olukhulu lwezinsalela zaseMiddle Cretaceous ezitholakala eningizimu-ntshonalanga yeMontana, eduze kwedolobha laseLima. Ekuqaleni, le nto yayingabonakali imangalisa kakhulu: izinsalela zezingcezu ze-carapace ne-plastron, ezingenalo ugebhezi noma izitho , ezingezohlobo lwengane encane engaba yimitha elilodwa ubude.
Ithimba lasensimini laliholwa nguJack Prall, owayengumfundi we-undergraduate ngaleso sikhathi , ephelezelwa ngumfundi we-postgraduate uBrendan Clark kanye namanye amalungu ahlobene ne- Museum of the Rockies kanye ne-MSU Department of Earth Sciences . Abafundi baqambe lesi silwane ngokuthi “uDonatello,” ngemuva komlingiswa we-Teenage Mutant Ninja Turtle, ukunqekuzisa ikhanda okuphikisana nokubaluleka okukhulu kwesayensi kwalokhu kutholwa.
Sekungamashumi eminyaka, izazi ze-paleontologists zaseNyakatho Melika zazijwayelene kakhulu ne -Basilemys : ufudu olukhulu, oluqinile, olunegobolondo elijiyile , oluvame kakhulu ezindaweni zokugcina ze-Late Cretaceous, ikakhulukazi phakathi kweminyaka eyizigidi ezingu-84 nezingu-66 edlule. Kodwa-ke, wonke amarekhodi athembekile ohlobo awela ngaphakathi kwaleso sikhathi, eshiya igebe elikhulu olwazini lwethu mayelana nemvelaphi yalo kanye nokufika kwalo kuleli zwekazi.
Isimanga senzeke lapho ithimba le-geochronology, eliholwa nguSolwazi Devon Orme kanye nomfundi uZak Hannebaum , lihlaziya ngokuningiliziwe inhlabathi ezungeze insalela. Besebenzisa i-uranium-lead dating yama-zircons alahlekile, bakwazi ukuthola ubudala besendlalelo esiqukethe insalela cishe eminyakeni eyizigidi ezingu-89 ubudala . Lokhu okutholakele kwenza uDonatello waba yisibonelo seBasilemys esidala kunazo zonke futhi kwaphoqa imvelaphi yohlobo oluqinisekisiwe eNyakatho Melika.
Njengoba uPrall ngokwakhe echazile, lapho imiphumela yelabhorethri ibuya, isimo eqenjini sasisebenza kahle: izibalo zaqinisekisa ukuthi ufudu lwaluphila ngesikhathi se-Middle Cretaceous , hhayi ekupheleni kwenkathi njengoba kwakucatshangwa ngaphambili. Lokho okwakubonakala sengathi yi-fossil engavamile kwavele kwaba yingxenye ebalulekile yokulungisa isikhathi sokufuduka kwezilwane.
Ufudu lwase-Asia oluwele eMelika ngaphambi kwesikhathi esibekiwe
Ukubaluleka kwalokhu kutholwa kudlulela ngalé kokwengeza nje insalela eqoqweni. AmaBasilemy angowomndeni wakwaNanhsiungchelyidae ongasekho , iqembu lezimfudu ezivela e-Asia . Zonke izihlobo zazo ezaziwayo zitholakale e -Eurasia , kanti lolu hlobo luwukuphela komele umndeni okhona eNyakatho naseMelika Ephakathi.
Lokhu kusabalala okungalingani kakhulu kwenza iBasilemys ibe yinkomba enelungelo lokushintshisana kwezilwane phakathi kwe-Asia neNyakatho Melika . Kuze kube manje, njengoba kunamarekhodi athembekile asukela eminyakeni eyizigidi ezingu-84 kuphela edlule, imicabango yokuthi ukuwela phakathi kwamazwekazi kwenzeke nini yayibanzi kakhulu. Lezi zinsalela ezintsha ziphoqelela incazelo entsha yalezo zilinganiso.
Njengoba i -Frontier Formation isukela eminyakeni engaba yizigidi ezingu-89,9 , abacwaningi baphetha ngokuthi ukufika kokhokho bakaBasilemys eMelika kumelwe ukuba kwenzeka ngaphambi kweminyaka eyizigidi ezingu-90 edlule . Isimo esingenzeka kakhulu sikhomba ibhuloho lomhlaba lendabuko laseBeringia , ucezu lomhlaba oluxhumanisa iSiberia ne-Alaska lapho amazinga olwandle ayephansi, njengendlela lezi zimfudu ezazivame ukuwela ngayo.
Amamodeli e-paleoclimatic acashunwe ocwaningweni abonisa ukuthi, ngesikhathi se-Cenomanian-Turonian Thermal Maximum, amazinga okushisa ajwayelekile ezindaweni eziphansi ayengafinyelela cishe ku-13 °C . Ezweni elinesimo sezulu esifudumele futhi elingenazo iziqongo zeqhwa ezihlala njalo, izilwane ezihlala ezindaweni ezishisayo njengezimfudu bezingakwazi ukuhamba ezindaweni eziphakeme kalula kakhulu kunanamuhla, into exhumanisa noshintsho lwesimo sezulu lwanamuhla kanye nezimfudu zasolwandle.
Kulesi simo, isibonelo saseMontana sibonisa ukuthi amaBasilemys awazange afike nje kuphela ezwekazini laseMelika kodwa futhi aqoqa ngokushesha iNyakatho Melika entshonalanga , azinza ezindaweni ezazisakazekela eningizimu ye-Alaska neCanada yanamuhla. Ukuba khona kwawo endaweni ephansi kakhulu kubonisa ukuthi lezi zilwane ezihuquzelayo zasebenzisa ngokushesha amathuba amasha emvelo anikezwa yiplanethi efudumala ngokushesha.
Ukuphila eplanethini engenaqhwa kanye nobumnyama be-polar
Nakuba i-Cretaceous yayiyinkathi efudumele ngokumangalisayo, lokhu kutholwa kuphakamisa umbuzo ongakhululekile: la mafudu angasinda kanjani ezimweni ezingavamile zezifunda ezisenyakatho , ezinezinyanga ezinde zobumnyama kanye nokushintsha kwezinga lokushisa kwesizini, ngisho nangaphandle kwamaqhwa ahlala njalo?
Lolu cwaningo luphakamisa amathuba amaningana asekelwe ekuqhathanisweni nezimfudu zanamuhla kanye nokwakheka kukaBasilemys . Konke kukhomba esilwaneni esihlala emhlabeni esinegobolondo elikhulu, elihlotshisiwe , esifana kakhulu nendlela yokuphila nezimfudu zanamuhla ezifudumele kunezinhlobo zasemanzini. Lokhu kwakheka komzimba kusikisela ukuthi kungenzeka ukuthi kusebenzise amasu okuvikela emakhazeni nasezinhlotsheni zesizini.
Phakathi kwemibono enengqondo kakhulu umbono wokuthi la mafudu ayeyi -fossorial okungenani ingxenye yawo, ekwazi ukumba imigodi yokukhosela phakathi nezinyanga ezinzima kakhulu. Kuphakanyiswa nokuthi angangena ezimweni zokuphelelwa amandla kwesizini okufana nokuqhuma kwemisipha okwenziwa namuhla yizinhlobo eziningi zamafudu asemhlabeni lapho amazinga okushisa ehla.
Indawo ezungezile uDonatello ayehlala kuyo iqinisa lezi zincazelo. Ngaleso sikhathi, ingxenye enkulu yangaphakathi yeNyakatho Melika yayihlalwa ulwandle olukhulu oluphakathi nezwe olwaluhlukanisa izwekazi libe yizindawo ezimbili zomhlaba. AmaBasilemys ngabe ahlala ogwini olusentshonalanga lwalolo lwandle, ezindaweni ezifudumele nezinomswakama ezinezitshalo eziluhlaza , ehlala nezingwenya zasendulo, ama-dinosaur amancane adla uhlaza futhi adla inyama, kanye nezinye izilwane ezinomgogodla zasemhlabeni.
Ezindaweni eziseduze, njenge- Blackleaf Formation , kuye kwachazwa ama-dinosaur ahlala emigodini njenge- *Oryctodromeus cubicularis* , atholakale eceleni kwamaphuphu awo emigodini efakwe izinsalela. Ama-crocodyliform asemhlabeni asukela eminyakeni engaba yizigidi ezingu-95 nawo atholakale , abonisa izici zomzimba ezifana nezinhlobo ze-Cretaceous ezivela e-Afrika naseNingizimu Melika, okuphakamisa izinqubo zokuziphendukela kwemvelo ezifanayo emazwenikazi ahlukene. Konke lokhu kubonisa ukuthi ukuhlala emigodini nokuphephela ngaphansi komhlaba kwakuyisu elibanzi kulezi zindawo zemvelo.
Ingcezu yezinsalela ezinemiphumela yomhlaba wonke
Ngokombono we-anatomical kuphela, isampula ye-Frontier Formation ayiphelele kakhulu ukuchaza uhlobo olusha . Ugebhezi alukho, amapuleti amaningi egobolondo onakele, futhi ulwazi oluncane lokuxilonga lulinganiselwe. Noma kunjalo, lokhu akuzange kunciphise ukukhanga kukaDonatello emphakathini wesayensi nakancane.
Inani layo lisekuqondeni komongo wayo we-geological kanye ne-geochronological . Ukukwazi ukuhlanganisa ngokuzethemba kangaka i-fossil nesikhathi esineminyaka eyizigidi ezingu-89 ubudala esifundeni esibalulekile kwi-paleontology yaseNyakatho Melika kwenza lesi sibonelo sibe yindawo ebalulekile yokuqhathanisa esikhathini esizayo. Akuyona into yakho evamile emangalisayo yemyuziyamu, kodwa kunalokho i-fossil esiza ukulungisa izikhathi kanye nokulinganisa imibono mayelana nokufuduka kanye nezinguquko zemvelo.
Lolu cwaningo, olushicilelwe kumagazini i -Historical Biology , lugcizelela nokubaluleka kokuqhubeka nokuhlola ukwakheka okungakaqashelwa kuze kube manje . I-Frontier Formation kanye nomakhelwane bayo baziwa kakhulu ngezinyathelo ezimbalwa kanye nokutholwa okuhlukile, kodwa i-Donatello Formation ikhombisa ukuthi isenolwazi olubalulekile mayelana ne-Middle Cretaceous.
Kubacwaningi abanjengoPrall noClark, le miphumela ingena engxoxweni yamanje: ukuthi izilwane zisabela kanjani ezigabeni ezisheshayo zokufudumala komhlaba . Inkathi yeCretaceous, ngalomqondo, isebenza njengelabhorethri yemvelo yesimo sezulu esibi kakhulu, kanti ububanzi bezimfudu ezifana neBasilemys bunikeza isibonelo esicacile sendlela izilwane ezinomgogodla ezishintshe ngayo ukusatshalaliswa kwazo ngenxa yokushisa okukhuphukayo.
Ukuqhathanisa okwenzeka eminyakeni ecishe ibe yizigidi ezingu-90 edlule nezinguquko izimfudu nezinye izilwane ezihuquzelayo zomhlaba ezibhekana nazo namuhla kunganikeza izinkomba eziwusizo zokuhumusha izimpendulo zezilwane zanamuhla eplanethini efudumele kanye nokuqondisa imizamo yokuvikela izimfudu zasolwandle . Nakuba izimo zingafani, i-paleontology inikeza umbono obalulekile wesikhathi eside wokubeka izitayela zamanje esimweni.
IMontana njengefasitela leNkathi YamaDinosaur
Ukutholakala kweDonatello kunezela emasikweni amade emikhankasweni yasensimini kanye nokutholwa okubalulekile eningizimu-ntshonalanga yeMontana , okuye kwaqinisa lesi sifunda njengenye yezindawo zokucwaninga ezinkulu ezivulekile zokutadisha izilwane ezinomgogodla zaseCretaceous.
Ngo-2004, e-Blackleaf Formation eseduze, kwatholakala izinsalela zesilwane esikhulile kanye nezinsana ezimbili ze- *Oryctodromeus cubicularis* , i-dinosaur encane edla uhlaza, okwanikeza ubufakazi bokuqala obucacile bokuthi zimba phansi futhi zinakekelwa ngabazali ngaphakathi kwazo . Eminyakeni eminingi kamuva, olunye uhambo lwachaza ingwenya encane, yasemhlabeni yasendulo cishe eminyakeni eyizigidi ezingu-95 eyedlule , enezici ezihambisanayo nezingwenya zaseCretaceous ezivela e-Afrika naseNingizimu Melika.
Isamba salokhu okutholakele sivumele ukwakhiwa kabusha okuningiliziwe kwendlela izindawo zemvelo zaseNyakatho Melika ezahlelwa ngayo phakathi nenkathi ephakathi neCretaceous , isikhathi eside ngaphambi kwesigaba sokugcina esidumile esibuswa yiTyrannosaurus nabangane bayo. Kulo mfanekiso wedatha, uDonatello manje usesikhundleni esivelele, enikeza ulwazi oluqondile mayelana nokukhula kokuqala kwezimfudu ezinkulu zomhlaba ogwini olusentshonalanga lolwandle olungaphakathi.
Abacwaningi bakholelwa ukuthi impilo yalolu fudu yayingeke ihluke kakhulu kweyalolu fudu ezindaweni ezifudumele zanamuhla : oluhamba kancane, mhlawumbe ludla izimila nezithelo eziphansi, futhi lusebenzisa indawo egudle ugu lolwandle njengendawo yalo eyinhloko yokuhlala. Izinguquko zesizini kanye nokwehluka kwezinga lolwandle kwakuyobe kunqume isigqi sempilo yalo yansuku zonke.
Naphezu kokulinganiselwa kwerekhodi lezinsalela—okuhlukaniswa ngokwencazelo—imikhankaso eqhubekayo eMontana kanye nokuhlanganiswa komsebenzi wasensimini, ukuhlaziywa kwe-sedimentological, kanye namasu okuqhathanisa athuthukile kwenze lesi sifundazwe saba yisilinganiso samazwe ngamazwe. EYurophu naseSpain, lapho i-paleontology nayo inezindawo ezibalulekile zeCretaceous, lezi zifundo zaseNyakatho Melika zisebenza njengohlaka lokubhekisela ekuchazeni ukufuduka kanye nezinguquko zezilwane emhlabeni jikelele.
Indaba kaDonatello ibonisa ukuthi izingcezu ezimbalwa zegobolondo, uma zihlelwe kahle, zingashintsha kanjani ukulandelana kohlu lozalo lonke futhi zicacise ukuthi amazwekazi ahlangana nini futhi kanjani ngesikhathi seNkathi yamaDinosaur . Kusukela egqumeni elinothuli eMontana kuya emakhasini ephephabhukwini lesayensi lomhlaba wonke, izinsalela zalolu fudu oluneminyaka eyizigidi ezingu-89 ubudala ziye zaba yisikhumbuzo sokuthi konke okusha okutholiwe, noma ngabe kungabonakala kuncane kangakanani, kungasiphoqa ukuthi silungise ukuqonda kwethu ngesikhathi esidlule seplanethi.
