Ib txoj kev tshawb fawb tsis ntev los no tau ua raws li kev soj ntsuam ntawm cov pob zeb uas muaj hnub nyoog 518 lab xyoo thiab muaj cov pob txha qub tshaj plaws uas cov kws tshawb fawb tam sim no tau sau tseg. Raws li kev tshawb fawb, cov poj koob yawm txwv ntawm ntau yam tsiaj muaj sia nyob niaj hnub no tuaj yeem nyob ntau dua 500 lab xyoo dhau los hauv Suav teb niaj hnub no.
Hauv Yunnan, sab hnub poob ntawm Tuam Tshoj, cov kws tshawb fawb tau tshawb pom ib pawg qub tshaj plaws ntawm cov tsiaj fossils tam sim no paub txog kev tshawb fawb, muaj cov seem ntawm ntau dua 250 hom.
Nws yog ib qho tseem ceeb ntawm cov ntaub ntawv Cambrian Explosion, uas pom kev sib kis ceev ceev ntawm ob hom tsiaj - tsiaj uas, zoo li cov tsiaj niaj hnub thiab tib neeg, muaj kev sib haum xeeb li embryos, txhais tau tias lawv muaj sab laug thiab sab xis uas yog daim iav duab ntawm ib leeg.
Fossils nrhiav tau ntawm 518 lab-xyoo-laus Chengjiang Biota suav nrog worms, arthropods (cov poj koob yawm txwv ntawm cov cw nyob, kab, kab laug sab, thiab scorpions), thiab txawm tias cov vertebrates ntxov tshaj plaws (cov poj koob yawm txwv ntawm ntses, amphibians, tsiaj reptiles, noog, thiab tsiaj txhu) . Qhov kev tshawb pom ntawm txoj kev tshawb fawb tsis ntev los no tau nthuav tawm thawj zaug uas ib puag ncig no yog qhov dej ntiav dej hiav txwv uas muaj cov khoom noj muaj txiaj ntsig thiab tau cuam tshuam los ntawm dej nyab los nag.
Txawm hais tias thaj chaw tam sim no nyob rau hauv thaj av hauv roob roob ntawm Yunnan, pab pawg tau tshuaj xyuas cov qauv pob zeb uas qhia cov pov thawj ntawm cov dej ntws hauv dej hiav txwv hauv ib puag ncig uas muaj yav dhau los.
"Lub Cambrian Explosion tam sim no tau lees paub thoob ntiaj teb raws li qhov xwm txheej hloov pauv sai sai, tab sis cov laj thawj rau qhov xwm txheej no tau sib cav ntev, nrog kev xav ntawm ib puag ncig, caj ces, lossis kev coj noj coj ua," hais tias tus kws sau ntawv laus Dr. Xiaoya Ma, kws kho mob palaeobiologist ntawm University of Exeter thiab Yunnan University.
"Qhov kev tshawb pom ntawm ib puag ncig deltaic tso lub teeb tshiab rau kev nkag siab txog qhov ua rau muaj feem cuam tshuam rau kev vam meej ntawm Cambrian bilaterian tsiaj-dominated marine zej zog thiab lawv tshwj xeeb cov ntaub so ntswg preservation."
"Cov kev ntxhov siab ib puag ncig tsis ruaj khov kuj tseem tuaj yeem ua rau hloov pauv hluav taws xob ntawm cov tsiaj thaum ntxov."
Tus kws sau ntawv Farid Saleh, los ntawm Yunnan University, tau hais tias: "Peb tuaj yeem pom los ntawm kev sib koom ua ke ntawm ntau cov dej ntws ntws uas ib puag ncig hosting Chengjiang Biota yog qhov nyuaj thiab muaj qhov tob dua li qhov tau hais yav dhau los hauv cov ntaub ntawv rau cov zej zog zoo sib xws."
Changshi Qi, lwm tus kws sau ntawv ua ke thiab tus kws tshaj lij geochemist ntawm Yunnan University, ntxiv: "Peb cov kev tshawb fawb qhia tau hais tias Chengjiang Biota feem ntau nyob hauv ib puag ncig zoo-oxygenated dej ntiav-dej deltaic."
"Cov cua daj cua dub thauj cov kab mob no mus rau qhov chaw uas tsis muaj oxygen nyob ib sab, ua rau muaj kev tshwj xeeb tshwj xeeb uas peb pom niaj hnub no."
Co-sau Luis Buatois, kws kho mob paleontologist thiab sedimentologist ntawm University of Saskatchewan, tau hais tias: "Lub Chengjiang Biota, zoo li cov ntaub ntawv zoo sib xws faunas tau piav qhia nyob rau lwm qhov, yog khaws cia rau hauv cov khoom zoo-grained deposits."
"Peb txoj kev nkag siab txog yuav ua li cas cov av nkos tau tso tawm tau hloov pauv ntau hauv 15 xyoo dhau los."
"Kev thov ntawm qhov kev paub tsis ntev los no rau kev kawm ntawm fossiliferous deposits ntawm kev khaws cia tshwj xeeb yuav hloov pauv peb txoj kev nkag siab txog yuav ua li cas thiab qhov twg cov sediments tau sau tseg."
Qhov kev tshawb pom ntawm kev tshawb fawb yog qhov tseem ceeb vim lawv qhia tias feem ntau ntawm cov tsiaj thaum ntxov tau hloov mus rau qhov nyuaj ib puag ncig xws li salinity fluctuations thiab loj ntim ntawm sediment deposition.
Qhov no cuam tshuam qhov kev tshawb pom ntawm cov kev tshawb fawb yav dhau los, uas tau qhia tias cov tsiaj uas muaj cov yam ntxwv zoo ib yam ua rau cov dej tob tob thiab cov dej hauv hiav txwv nrog kev ruaj khov dua.
"Nws nyuaj rau ntseeg tias cov tsiaj no muaj peev xwm tiv nrog qhov kev ntxhov siab ib puag ncig," hais tias M. Gabriela Mángano, tus kws kho mob paleontologist ntawm University of Saskatchewan, uas tau kawm lwm qhov chaw paub zoo txog kev khaws cia tshwj xeeb hauv Canada, Morocco, thiab Greenland.
Maximiliano Paz, tus kws kho mob tom qab kawm tiav ntawm University of Saskatchewan uas tshwj xeeb hauv cov txheej txheem zoo, ntxiv: "Kev nkag mus rau cov cores sediment tau tso cai rau peb pom cov ntsiab lus hauv cov pob zeb uas feem ntau nyuaj rau kev txaus siab rau cov huab cua tawm ntawm Chengjiang cheeb tsam."
Daim ntawv, luam tawm nyob rau hauv phau ntawv journal Nature Communications, muaj cai: "Lub Chengjiang Biota nyob ib puag ncig deltaic"
