El Isikhathi seCambrian kungowokuqala ukuqamba inkathi yePaleozoic. Kwaqala cishe eminyakeni eyizigidi ezingama-541 edlule futhi kwaqhubeka kwaze kwaba cishe eminyakeni eyizigidi ezingama-485 edlule. Kukulesi sikhathi lapho iplanethi yethu ibone ukwehlukahluka okukhulu nokwandiswa kwempilo ekhona. I- Izilwane zaseCambrian Wayengu-protagonist walokho okuthiwa yi- «Cambrian Explosion». Kulapha lapho kwavela khona inqwaba yezinhlobo zezilwane ezazivele zinama-multicellular futhi ezaqala ukugcwala olwandle.
Kulesi sihloko sizokutshela ngazo zonke izici nokuvela kwezilwane zaseCambrian.
Isikhathi seCambrian
Okokuqala, sizobuyekeza ezinye zezici eziyinhloko zalesi sikhathi sesikhathi sokuma komhlaba. Ngenye yezikhathi ze-geological ezifundwe kakhulu ngochwepheshe be-paleontologist. Futhi ukuthi kube nezinguquko eziningi ezingeni le-geological kanye nokuvela kwezinto eziphilayo ezikhona. Konke lokhu kudalwe ushintsho olukhulu ezimweni zemvelo ezazikhona ngaleso sikhathi. Siyazi ukuthi lesi sikhathi sithathe cishe iminyaka eyizigidi ezingama-56. Phakathi kwezici eziyinhloko sithola ukwehlukahluka nokuvela kwezinto eziphilayo ezagcwala iplanethi.
Ngenxa yalolu shintsho, imiphetho emisha yezidalwa eziphilayo yaqala ukubakhona egcinwe kuze kube namuhla. Ngokuphathelene nokwakheka komhlaba, phakathi kwezinguquko ezibaluleke kakhulu ukuhanjiswa nokuhlukaniswa kwamazwe amakhulu akhona. Ochwepheshe abaningi baqinisekisa ukuthi kunezingcezu ezahlukahlukene zoqweqwe lomhlaba ezazisesikhathini seCambrian nokuthi zaziwumphumela wokuqhekeka kwezwekazi elikhulu kakhulu. Izwekazi le-super libize IPannotia yahlukaniswa yaba ezinye ezine ezaziwa ngegama lika: Gondwana, Baltica, Laurentia kanye neSiberia.
Ijubane lokukhuphuka kwezwekazi ngalesi sikhathi laliphakeme kakhulu kunanamuhla. Lokhu kubangele ukuthi izingcezu zihlukane ngejubane elikhulu. Mayelana nesimo sezulu, kunamarekhodi ambalwa kepha kukhona izinsalela ezithile zemvelo lapho kufundwe khona izici zemvelo. Kubikwa ukuthi ngesikhathi seCambrian amazinga okushisa ayephakeme kakhulu kunangezinye izinkathi zokwakheka komhlaba. Lokhu kungenxa yokuthi zazingekho izingcezu zeqhwa emhlabeni. Cishe lonke izwe elisenyakatho lalimbozwe ulwandle lwasePhantalassa kanti isimo sezulu sasipholile futhi siwuhlobo lwasolwandle.
Mayelana nesimo sezulu siyazi futhi ukuthi kube nokushayisana okuthile okwenzeka ngezikhathi ezithile zonyaka ngendlela yokuthi kuthiwe azibanga nezinguquko eziningi ngokuzumayo. Kodwa-ke, abanye ochwepheshe bathi ekupheleni kweCambrian ukwehla kwezinga lokushisa komhlaba kungabonakala. Lokhu kubangela ukuthi izwekazi elithile elalihamba kancane limbozwe yiqhwa.
ukuphila
Ngokuphathelene nokuphila kulesi sikhathi kunalokho okubizwa ngokuthi yiCambrian explosion lapho kwenzeka khona ukwehluka okungafani kwazo zonke izinhlobo zokuphila. Yize impilo yavela ku-Aronic aeon, kwakungakaze kube yileso sikhathi seCambrian lapho likwazile ukwehlukahluka kwazise impilo yonke ibilula kakhulu. Lo mkhuba waziwa ngoba izinhlobo eziningi zezilwane zingashintsha. Ukwehluka okukhulu kwezinto eziphilayo kwavela cishe ngasikhathi sinye. Ngenxa yamarekhodi ezimbiwa phansi, kutholakale inani elikhulu lolwazi. Izizathu zokuqhuma kweCambrian azikwazanga ukusungula ngqo ukuthi zaziyini iziqalo impilo engahluka ngazo.
Kulinganiselwa ukuthi bekuyizimbangela ezilandelayo:
- Khulisa umoya-mpilo osemkhathini
- Ukwandiswa kwamazinga e-ozone kusendlalelo lwe-ozone nokuvikelwa emisebeni eyingozi ye-ultraviolet.
- Khuphula izinga lolwandle. Lokhu bekusho ukuthi amathuba okwakhiwa kwenani elikhulu lezindawo zokuhlala, izinto eziphilayo emvelweni, ngakho-ke, inani elikhulu lezinhlobo zingakhuphuka.
Izilwane zaseCambrian
Izilwane zaseCambrian zihlala ikakhulukazi emanzini. Yonke imvelo yayinabile kakhulu futhi itholakala olwandle. Iningi lezilwane ezakha izilwane zaseCambrian zaziyizilwane ezingenamgogodla eziyinkimbinkimbi. Lapha sithola ama-trilobites, amanye ama-invertebrate amakhulu namanye amaqembu afana nawo yizimbungulu, izipanji nezikelemu. Sizohlaziya ngazinye izinhlobo ezigcwele kakhulu zezilwane zaseCambrian:
Izipanji
Ngalesi sikhathi kwakujwayelekile ukuthola izipanji eziningi olwandle. Namuhla zihlukaniswa onqenqemeni lwe-poriferous. Isici sayo esikhulu ukuthi kube nezingodo kuso sonke isakhiwo saso. Ngalezi zimbotshana zisiza ukujikeleza futhi hlunga izakhamzimba ezitholakala emanzini. Amarekhodi ezinsalela zalezi zinto eziphilayo asizile ukuthola ulwazi mayelana nokukhula kwalezi zilwane ngaleso sikhathi. Ngenxa yale mibhalo egciniwe yezinsalela, kuyaziwa ukuthi kwakukhona izipanji ezifana nezakhiwo zezihlahla nezinye ezinesimo sesigaxa.
Ama-arthropods
Kwakuyizilwane ezithuthuke kakhulu neziningi. Namuhla, zihlala ziyi-phylum eningi kakhulu yezilwane embusweni wezilwane. Kuzilwane zaseCambrian lokhu bekungafani. Ngaphakathi kwaleli qembu, sithola abamele kakhulu njengama-trilobites. Bachichima kulesi sikhathi sokucishe bagcina ubukhona babo kuze kube sekupheleni kwe- Isikhathi sePermian. Babengenye yezilwane zokuqala ukuthuthukisa umuzwa wokubona.
Izilwane zaseCambrian: ama-mollusks
Ama-mollusks abe nokuguqulwa okukhulu okuhlukahlukene ezigabeni ezahlukahlukene. Ezinye zazo zisatholakala nanamuhla. Sine-gastropods nama-cephalopods, phakathi kwabanye.
Ama-Echinoderms
Kwakunokunwetshwa okuningi nokuhlukahluka phakathi nalesi sikhathi. Izinhlobo ezintsha zama-echinoderms zavela ezingakwazi ukuzivumelanisa nezimo ezahlukahlukene ezikhona zemvelo. Isigaba esasinda isikhathi eside kunazo zonke kwakuyi-crinoid.
Izilwane zaseCambrian: izingxabano
Kwakuyiqembu lezilwane elibaluleke kunazo zonke ukuthi lalinomsuka walo kule nkathi. Ngenxa yalezi zilwane kuyaziwa ukuthi izilwane zaseCambrian zahlukanisa inani elikhulu lamaqembu anjenge izilwane ezinomgogodla phakathi kwazo esinezilwane eziphila ezweni, izinhlanzi, izilwane ezinwabuzelayo, izinyoni nezilwane ezincelisayo. Isici esihlukile salezi zilwane ukuthi zinesakhiwo esaziwa njenge-notochord. Ngakho-ke igama liyaxakaniseka. I-notochord iyintambo ye-tubular efinyelela kuyo yonke ingxenye yokuhlanya yomuntu ngamunye futhi inomsebenzi wokwakha. Isistimu yezinzwa ephakathi, umsila we-post-anal, ne-pharynx enezimbobo nakho kukhona.
Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi ngezilwane zaseCambrian nezimpawu zazo.