Ukufunyanwa ‘Kwezirhubuluzi Ezikhulu’ Zamhlamnene

XA UMI emdeni wentlambo yoMlambo iRed Deer, emazantsi kanye edolophu iDrumheller eseAlberta, eKhanada, umi emdeni wamazwe amabini awahlukahlukeneyo. Macala onke, apho iliso lakho linokufikelela khona, kuthe tyaba amasimi engqolowa kumathafa aseAlberta. Kodwa xa bejonge emazantsi eliwa elimqengqelezi kwintlambo engumqwebedu nebharhileyo, abantu abatyeleleyo banokucinga ngelizwe elahluke mpela kwelo bakulo​—⁠ilizwe lezirhubuluzi zamandulo (dinosaurs).

Kule ntlambo, enemiwonyo emqengqelezi yeengcamba zamatye entlenga anemibala emininzi, kuye kwavunjululwa amathambo amaninzi ezirhubuluzi zamandulo. Abanye abantu abakuloo mmandla bayibiza le ntlango ibharhileyo ngokuthi “kukwanti zitshile.” Kodwa abantu abatyeleleyo, abatsha nabakhulileyo ngokufanayo, babamb’ ongezantsi njengoko bebona iifosili zamhlamnene zezinye zezona zilwanyana zimangalisayo ezakha zaphila emhlabeni.

Ukufunyanwa Kwezirhubuluzi Zamandulo

Ngaphambi kowe-1824, izirhubuluzi zamandulo zazingaziwa ngabantu. Ngaloo nyaka, eNgilani kwavunjululwa amathambo eentlobo ezininzi zezirhubuluzi ezazenziwe iifosili. Isazinzulu ngezidalwa zamandulo saseBritani uRichard Owen wazibiza ezi zilwanyana ngokuba ziiDinosauria, (Izirhubuluzi Ezikhulu Zamandulo) gama elo elithatyathwe kumagama amabini esiGrike elithi deinos nelithi sauros, athetha “icilikishe eloyikekayo.” Eli gama lisasetyenziswa ngokuqhelekileyo ukuza kuthi ga namhlanje, nangona iidinosaur zizizirhubuluzi, azingawo amacilikishe.

Ukususela ngowe-1824, iifosili zezirhubuluzi zamandulo ziye zafunyanwa kuwo onke amazwekazi. Ingxelo engezi fosili, ezashiyeka kwiingcamba zamatye entlenga, okanye zamatye angaphantsi kwamanzi, ibonisa ukuba ngaxa lithile kwimbali yomhlaba elibizwa ngokuba liXesha Lezirhubuluzi Zamandulo kwakukho iintlobo ezininzi ngokugqithiseleyo nezahlukahlukeneyo zezirhubuluzi zamandulo. Zimbi zazihlala emhlabeni owomileyo, ngoxa ezinye zazihlala emigxobhozweni. Kunokwenzeka ukuba zimbi zazikwahlala nasemanzini, ngokufana nqwa neemvubu ezikhoyo namhlanje.

Amathambo amaninzi gqitha aseleyo ezirhubuluzi zamandulo​—⁠kuquka nobungqina obungengawo amathambo obunjengemizila yazo⁠—​aye avunjululwa kwiThafa Elikhulu elikuMbindini woMntla Merika. Kumathafa athe tyaba akumbindi weAlberta kuye kwavunjululwa izinto ezasalayo zezirhubuluzi zamandulo, kuquka izakhelo ezingamathambo zomzimba ezimalunga nama-500. Kwiminyaka yee-1920, abahambi bafumana amathambo esirhubuluzi samandulo kwiNtlango iGobi ekumbindi Asiya. Kwiminyaka yee-1940 umhambi ongumRashiya wafumana isakhelo esingamathambo somzimba wesirhubuluzi samandulo eMongolia esasimalunga neemitha ezili-12 ubude.

Ngowe-1986 izazinzulu zaseArgentina zafumana iifosili zesirhubuluzi samandulo esitya utyani eAntarctica. De kube ngoko, iAntarctica iye yaba kuphela kommandla omkhulu womhlaba apho bekungazange kufunyanwe iifosili zezirhubuluzi zamandulo. Ngaphambi koko, umphengululi waseMerika wayesandul’ ukufumana amathambo esirhubuluzi samandulo kuMntla weThambeka laseAlaska. Kuyo yonke le minyaka ilikhulu idluleyo, kuye kwavunjululwa amathambo amaninzi ezirhubuluzi zamandulo kwiindawo ezininzi kakhulu kangangokuba kuye kwabonakala ukuba izirhubuluzi zamandulo zazisasazeke kuyo yonke indawo kwixesha eladlulayo.

Zaziphila Nini?

Izirhubuluzi zamandulo zazininzi gqitha apha emhlabeni ngexesha lazo. Kodwa zandula ke zafikelela esiphelweni sazo. Iingcamba zamatye ezineefosili zabantu zisoloko zisiba ngaphezu kweengcamba ezineefosili zezirhubuluzi zamandulo. Ngenxa yoku, ngokubanzi izazinzulu ziqukumbela ngelithi abantu babakho emhlabeni emva kwazo.

Ngokuphathelele oku incwadi ethi Palaeontology, ebhalwe nguJames Scott, ichaza oku: “Kwanezona ntlobo zokuqala zeeHomo sapiens (abantu) zabakho emva lee kokuthi shwaka kwezirhubuluzi zamandulo . . . Nangona iingcamba zomhlaba ziye zema ngenye indlela nto leyo ebangelwa kukushukuma komhlaba, amatye aneefosili zabantu asoloko esiba ngaphezu kwalawo anamathambo ezirhubuluzi ezikhulu zamandulo ibe umphumo ubonisa ukuba ezi zirhubuluzi zabakho kwiminyaka engaphambilana kunamathambo aseleyo abantu.”

Kwintlambo yoMlambo iRed Deer, kukho ucamba lwelitye lentlenga ekukho kulo amathambo ezirhubuluzi zamandulo. Kanye ngaphezu kolu camba, kukho olunye ucamba olumdaka bumthendevu lulandela ukumila kwenduli. Ngaphezu kolu camba lumdaka bumthendevu kukho ucamba lwelitye lentlenga olubumdaka oluneefosili zesityalo inkomankoma esikhula nganeno kwenjiko, ezibonisa imo yezulu eshushu. Phezu kwalo, kukho iingcamba ezininzi zelahle. Ngaphezulu kuhle kwethambeka lenduli kukho iingcamba ezirhabaxa zomhlaba. Awakho amathambo ezirhubuluzi zamandulo kuzo naziphi na iingcamba ezingaphezulu.

Incwadi ethi A Vanished World: The Dinosaurs of Western Canada ichaza isithi “zonke iintlobo ezili-11 eziphambili zezirhubuluzi zamandulo . . . zaphela kummandla ongasentshona malunga nexesha elinye.” Oku, ndawonye nesibakala sokuba amathambo abantu engazange afunyanwe enamathambo ezirhubuluzi zamandulo, kusisizathu esibangela ukuba izazinzulu ezininzi zigqibe ngelithi Ixesha Lezirhulubuzi Zamandulo laphela ngaphambi kokuba abantu babekho.

Phofu ke, ifanele iphawulwe into yokuba kukho abanye abathi amathambo ezirhubuluzi zamandulo namathambo abantu awafunyanwa ndaweninye kuba izirhubuluzi zamandulo zazingahlali kwimimandla eyayinabantu. Iimbono ezahlukene ngolo hlobo zibonisa ukuba ingxelo engeefosili ayiyivelisi imfihlelo yayo ngokulula kangako yaye zikwabonisa nokuba akukho namnye emhlabeni namhlanje ozaziyo ngokwenene zonke iimpendulo.

Iimpawu Zazo

Izazinzulu ziye zagqiba ngelithi kwicala langasempuma leeNtaba iiRocky ezikuMntla Merika, kwakukho ulwandle olukhulu olungenzulu. Olu lwandle lwalungangeekhilomitha ezingamakhulu khulu ububanzi, luqalela kuLwandlekazi lweArtic olukhoyo ngoku ukuya eMexico. Ngaselunxwemeni kwakukho amahlathi achumileyo, nakhula kwindawo engumgxobhozo. Ubukho beefosili bubonisa ukuba iintlobo ezininzi zezirhubuluzi zamandulo zaziphila kakuhle kule ndawo zazihlala kuyo. Kuyabonakala ukuba, iiedmontosaurus, izirhubuluzi zamandulo ezinomlomo wedada nezinobude obuziimitha ezisisithoba, zazihamba ngokwamaqela njengemihlambi yeenkomo emigxobhozweni. Imizila esabonakalayo yeenyawo ezineenzwane ezintathu neefosili ezafumaneka esiswini zakhokelela izazinzulu ngezidalwa zamandulo ukuba zifikelele kwesi sigqibo.

Obunye ubungqina bubonisa ukuba ezinye izirhubuluzi zamandulo zazibonakalisa imikhwa yobuhlobo. Ngokunokwenzeka zazihlanganisana njengomhlambi, mhlawumbi ngokwamaqela angamakhulu khulu okanye ngaphezulu. Ukufunyanwa kweengcamba zezindlu namaqanda ngokulandelelanayo kwindawo enye kubonisa ukuba ezinye izirhubuluzi zamandulo zazibuyela kwizindlwana zokuzalela amaqanda ezikwanye unyaka emva komnye. Amathambo asalayo ezirhubuluzi zamandulo ezincinane kufutshane nezi zindlwana, ‘akubonisa ngokunamandla ukuziphatha ngobuhlobo kwezirhubuluzi ezizalwa kunye ibe akwabonisa nenyameko ekusenokwenzeka ukuba wayesiba nayo umzali kwizirhubuluzi ezincinane emva kokuqanduselwa kwazo,’ ichaza ngaloo ndlela iScientific American.

Ngaloo ndlela ubungqina beefosili bubonisa ukuba kwakukho izirhubuluzi zamandulo ezininzi nezahlukahlukene gqitha. Kodwa kanye kanye yayinjani inkangeleko yazo? Ngaba zazingamarhamncwa awoyikekayo namakhulu ngokugqithiseleyo​—⁠“amacilikishe awoyikekayo”? Kwakutheni ukuze ziphel’ emehlweni ngequbuliso kangako?

[Inkcazelo Ngomfanekiso okwiphepha 3]

Smithsonian Institution, Washington, D.C.: Photo Number 43494