Namhlanje siza kuthetha malunga Izilwanyana ze-Ediacara. Yiseti yezinto eziphilayo ezimele zonke iintlobo zezilwanyana ezihlala eMhlabeni ngexesha le-geological eyaziwa ngokuba yi-Ediacara. Eli xesha lenzeka malunga neminyaka engama-600 yezigidi eyadlulayo. Kucingelwa ukuba le fauna inokunxulunyaniswa nokwanda kwamazinga eoksijini kwihlabathi liphela ngelo xesha.
Kule posi siza kuvavanya ngokupheleleyo izilwanyana zase-Ediacara ukufumana zonke iimfihlo zayo.
Umvelaphi
Izazinzulu zicinga ukuba izilwanyana zase-Ediacaran zinemvelaphi yokunyuka kweoksijini yomoya eyenzeka kwiminyaka ezizigidi ezingama-600 eyadlulayo. Le nyani ithande ukuphuhliswa kweemazozo zokuqala ezazineempawu ezifanayo: Umzimba ngokuthamba okuthambileyo kunye neemilo ezahlukeneyo. Ezi zilwanyana zifunyenwe kwindawo ye-paleontological efumaneka kwii-Ediacara Mountains, e-Australia.
Iirekhodi zeefosili zezi zilwanyana zigcinwa kwimimandla eyahlukeneyo yehlabathi. Le fauna imele ukukhula okubalulekileyo kwizinto eziphilayo ezininzi ngaphambi kokuqhushumba kweCambrian. Enye yeendlela zokuqala zobomi ezazidinga ioksijini emoyeni ukuze zikhule. Ukongeza, izazinzulu zicinga ukuba sisandulela sezinto eziphilayo ezinamathambo.
Ngaphandle kwenyani yokuba uMhlaba wasekwa kwiminyaka eyi-4550 yezigidigidi, bekungekho de kube yiProterozoic ukuba bekukho iatmosferi okanye inguquko yomoya onomoya ophezulu. Ngaphambili, zazikhona kuphela izinto ze-methanogenic, kuba uxinzelelo lwe-methane emoyeni yayiphezulu kakhulu kwaye ezi zinto zazilungele imeko ye-anaerobic.
Isigaba sokugqibela sexesha le-Neoproterozoic yinto eyaziwa ngokuba lixesha le-Ediacaran. Ekuqaleni kweli xesha lokuma komhlaba kuxa izidalwa ezindala ezinee-multicellular zaqala ukukhula. Ezi zinto zisekhona nanamhlanje kwaye zezona zidala esizaziyo. Ezi ziziponji zokuqala kunye neeanemones. Eli xesha lokuma komhlaba laqala kwiminyaka engama-635 yezigidi eyadlulayo yaphela kwiminyaka engama-542 yezigidi eyadlulayo.
Akukho mafosili ngaphambi kwezilwanyana zase-Ediacara
Enye yeenkcazo ezinokuthi zinikezwe kwinyani yokuba akukho fossil yazo naziphi na izilwanyana ezikhoyo ngaphambi kweli xesha le-geological kukuba izidalwa eziphilayo zangaphambili zazingenayo i-collagen. I-Collagen yiprotein enemicu enceda ukomeleza umzimba wesilwanyana kwaye iyivumele ukuba igcinwe ekuhambeni kwexesha.
Le khompawundi organic yenzeka kuphela xa inqanaba leoksijini esemoyeni likhulu kune-3%. Ngenxa yoko, i-collagen ayizange yenziwe kwangoko kwimeko ye-anaerobic.
Kukho iingcamango ezithile malunga nokufana phakathi kwezilwanyana ze-Ediacara kunye neefom zezilwanyana ezikhoyo. Enye inkolelo kukuba uninzi lwezi zilwanyana ngookhokho ngqo beentlobo esizaziyo namhlanje. Kwelinye icala, kukho enye intelekelelo yokuba izilwanyana zase-Ediacara zinokungafani kwaphela. Oku kuthetha ukuba ayinalo unxibelelwano nezinto eziphilayo esizaziyo namhlanje. Esi sizathu sokuba yahlulwe kwi-phylum eyahlukileyo eyaziwa njenge-extinct phylum Vendozoa.
Ukuba uvavanyo lwenziwe ngeefosili ezifumanekayo, siyabona ukuba ezinye iintlobo zezilwanyana ze-Ediacara ziyafana nezo zazihlala eCambrian. Le nyaniso ithetha ukuba, ngandlela thile, zinokunxulumana nezinto ezikhoyo ngoku. Omnye wemizekelo esetyenzisiweyo yile yeKimbelerra Cuadrata. Luhlobo olwahlala kwixesha le-Ediacaran kwaye lufana kakhulu neemollusk zangoku.
Kwaye, nangona zikhona ezinye iindlela ezibonakala ngathi ziyaphikisana, ubukho bezilwanyana zase-Ediacaran inokuba yingcaciso yokuvela kwezinto ezininzi ezikhoyo namhlanje.
Iimpawu eziphambili
Amathambo afunyenwe kwizidalwa zamandulo akhula ngokugquma ulwandle ngodaka nentlabathi entle. Le yindlela olwenziwa ngayo uxinzelelo oluthile kwimizimba esezantsi kwentlabathi. Njengoko inepesenti ephezulu yamanzi, yehlile kubukhulu, inika iifosili ukubonakala okuthe tyaba kwaye kujikeleze.
Ezi zilwanyana kucingelwa ukuba zazihlala kufutshane nezidumbu ezifumaneka kwishelufa yelizwekazi. Oku kwenze ukuba babenakho ukuhlala nzulu kwimida yelizwekazi eyayikho ngeli xesha.
De iirekhodi zeefosili ze-Ediacaran zifumene izinto eziphilayo ezinomzimba othambileyo. Oku kucingelwa ukuba kunjalo, kuba kukho iimilo zediski ezenziwa zizakhiwo ezinemithambo. Unokubona i-radials yangaphakathi okanye indibaniselwano yazo zombini.
Enye into yeefosili kukuba ezinye zafunyanwa zinamathambo angaqhelekanga kunye nama-amorphous awayenokubakho kwizakhiwo zamandulo ze-sporophytes.
Ukupheliswa kwezilwanyana zase-Ediacara
Kuyatshiwo ukuba ezi zilwanyana zaphela kwaphela kwi-Precambrian. Isizathu mhlawumbi ngenxa yokutyisa okunzima kwezi zilwanyana zakudala kunye nokwahluka okwabakho kwinqanaba lolwandle. Ukugqithisa emadlelweni kubangele ukuphela kwezityalo ezininzi ezazisebenza njengokuxhasa izilwanyana.
Nangona kunjalo, ngaphandle kwenkolelo yakudala, kuyaziwa ngokusuka kuphononongo olutsha ukuba ezinye iintlobo ze-Ediacaran zazihlala ngexesha le-Cambrian.
Ezinye zezizathu zokuba zonke iintlobo zezinto eziphilayo zitshabalale zezi:
- Glaciations: Ngamaxesha okubanda kakhulu enza izithintelo kwizinto eziphilayo zokukhula nokukhula.
- Ukutya: Zonke izinto eziphilayo ngexesha leCambrian zazingamarhamncwa. Ukuba esi sidalwa siqale ngexesha lokuncipha kwezilwanyana zase-Ediacara, yeyona nto iphambili ekuphelisweni kweentlobo ezininzi.
- Utshintsho kwezendalo. Utshintsho olukhulu lwejoloji, lwebhayoloji nolwemo yezulu olwenzeka ekupheleni kwe-Precambrian kunye nokuqala kweCambrian zenze uninzi lweentlobo alunakho ukuziqhelanisa neemeko zokusingqongileyo ezintsha.
Ndiyathemba ukuba olu lwazi ungafunda ngakumbi malunga nezilwanyana zase-Ediacara.