Esikhathini seMesozoic kunezikhathi ezi-3 ezihlukanisa imicimbi eyahlukene ephawule ukuqala nokuphela kokubili ezingeni le-geological and biological. Isikhathi sokuqala yiTriassic futhi namhlanje sizogxila enkathini yesibili yeMesozoic. Imayelana neJurassic. Kukwahlukaniswa kwesilinganiso sesikhathi sokuma komhlaba esiqale cishe eminyakeni eyizigidi eziyi-199 edlule futhi sagcina eminyakeni eyizigidi eziyi-145 edlule. Njengezikhathi eziningi ze-geologic, kokubili ukuqala nokuphela kwezikhathi akulona iqiniso ngokuphelele.
Kulesi sihloko sizokutshela zonke izici, i-geology, isimo sezulu, izimbali nezilwane ze-Jurassic.
Izici eziyinhloko
Yisikhathi lapho izehlakalo ezithile ezibalulekile zenzeke khona emhlabeni jikelele futhi lokhu kungemuva kweTriassic nangaphambi kweCretaceous. Igama leJurassic livela ezakhiweni ze-carbonate sedimentary ezenzeka esifundeni saseYurophu iJura, esise-Alps. Ngakho-ke igama liyiJurassic. Kuyo yonke le nkathi, esinye sezici ezisemqoka okugqame kakhulu ngaso wukuqhamuka kwama-dinosaurs amakhulu (okwenzelwe amafilimu amaningi) kanye nokwehlukaniswa kwezwekazi elikhulu iPangea emazweni aseLaurasia naseGondwana.
Kusuka engxenyeni ebizwa ngeGondawana, i-Australia yawa ngesikhathi se-Upper Jurassic nasekuqaleni kweCretaceous. Ngale ndlela efanayo, iLaurasia yahlukaniswa yaba yilokho esikwaziyo namuhla njengeNyakatho Melika ne-Eurasia, kwaveza izinhlobo zezilwane ezincelisayo ezahlukahlukene njengoba izimo zemvelo zashintsha kubo bonke.
I-geology yeJurassic
Lesi sikhathi sokuma komhlaba sihlukaniswe kakhulu saba ngaphansi, phakathi naphezulu. Lezi yizikhathi ezaziwayo esikhathini esithile. Inikezwe amagama athi Lias, Dogger, noMalm. Ngesikhathi seJurassic izinga lolwandle lahlangabezana nezinguquko ezimbalwa kodwa kuphela ngesikhathi sangaphakathi. Kakade ku-Jurassic engenhla, okunye ukushesha okusheshayo kungabonwa esikhathini esithile okwaholela ekukhuphukeni kolwandle okubanga ukukhukhula kwezindawo ezinkulu eNyakatho Melika naseYurophu.
Kulesi sikhathi singakhomba ezifundazweni ezimbili ze-biogeographic ezitholakala kulokho esikwaziyo namuhla njenge-Europe. Elinye laziwa ngokuthi yiTethys eningizimu kanti elinye liyibhora enyakatho. Yonke imifula yamakhorali bekufanele ivinjelwe ingxenye enkulu esifundazweni saseTethys. Inguquko eyayikhona phakathi kwezifundazwe ezimbili yayisendaweni manje eyiNhlonhlo Yase-Iberia.
Irekhodi lokwakheka kwesikhathi seJurassic lihle impela, ikakhulukazi entshonalanga yeYurophu. Futhi ukuthi kule ngxenye yezwekazi kwakukhona ukulandelana okubanzi kolwandle okukhombisa isikhathi lapho ingxenye enkulu yezwekazi yayicwiliswe ngaphansi kwezilwandle ezishisayo ezinokujula okuncane. Ngenxa yodumo lezi zindawo ezingaphansi kwamanzi ezigqamile, laziwa njengeGugu Lomhlaba loGu lweJurassic kanye ne-lagerstätten yaseHolzmaden neSolnhofen.
Isimo sezulu seJurassic
Ngalesi sikhathi, izitshalo ezazijwayele isimo sezulu esifudumele yizo ezazisakazeka cishe kuwo wonke umhlaba. Lezi zitshalo zikwazile ukunweba kuze kufike kuma-degree angama-60 latitude. Kokubili izimbali okwakungokwesula laseningizimu yeGondwana, enyakatho yeSiberia zazihlanganisa amaqembu amaningi ama-fern ayekwazi ukumelana nesithwathwa esiqinile. Namuhla, izihlobo zanamuhla zalawa maferns azikwazi ukumodela isithwathwa namazinga okushisa aphansi njalo.
Konke lokhu ukuba khona kwamazinga okushisa aphakeme kudale ukuthi izindawo ezibukeka zeJurassic zicebe ngohlaza kunalezo zeTriassic. Ikakhulu, bekukhona uhlaza oluningi ezindaweni eziphakeme. Njengoba kwakushisa impela futhi isimo sezulu esinomswakama sivumelekile ukunabela kuwo wonke amahlathi, amahlathi kanye namahlathi akha inani elikhulu lendawo ejwayelekile kumafilimu amaJurassic. Yile ndlela amahlathi nawo aqala ngayo ukusabalala ebusweni bomhlaba futhi imindeni efana nama-conifers afana namaphayini nama-araucarias agqamile, ahambisana nezinhlobo ezahlukahlukene zamafern nemithi yesundu. Ngokuqinisekile wonke la mazwe agcwele izitshalo ezithunyelwe azokhumbula amanye ama-movie weJurassic.
Izimbali nezilwane
Ngesikhathi seJurassic, izimbali zazinokubaluleka komhlaba wonke, ikakhulukazi ezindaweni eziphakeme. Kwakungewona amahlathi asemhlabeni kuphela ayegcwele ama-conifers nama-ferns amaningi, kepha nama-ginkgo nama-horsetails ayekhona. Ngalesi sikhathi, izitshalo ezinama-inflorescence azikabonakali. Siyakhumbula ukuthi, kuze kube manje, izitshalo ezisakazeke kakhulu emhlabeni jikelele ziseqenjini lama-gymnosperms, okungukuthi, lawo angenazo izimbali.
Ukusatshalaliswa okwehlukene kwezimbali kuyo yonke indawo yomhlaba kuyisibonakaliso sangempela sokwehlukana okwakukhona phakathi kwezindawo ezisenkabazwe nasenyakatho. Ukuthuthukiswa kwezinyamazane ezihlukanisiwe kubangelwe ukuba khona kwezithiyo eziningi zasolwandle ezazikhona phakathi kwenyakatho naseningizimu. Lezi zithiyo zasolwandle zalungiswa nge-gradient yokushisa enkulu eyasuka engxenyeni enkulu yesigxobo yaya e-Equator. Lezi gradients ezishisayo bezingakhuphuki njengoba zinjalo namuhla yize bungekho ubufakazi beqhwa le-polar ngesikhathi seJurassic. Lokhu kusho ukuthi umbono wokuthi amazinga okushisa abephakeme futhi abeyimbangela yokusabalala kwalolu hlobo lwezitshalo uyaqinisekiswa futhi.
Izimbali ezazikude nenkabazwe zazifanelana nezitshalo zezindawo ezinamazinga okushisa aphansi futhi zonke lezi zindawo ezingamaJurassic zazibizwa ngegama leCycadophyta. I-ginkgo namahlathi amabili e-coniferous ayenganaki yonke indawo. Isimanjemanje sihlala kepha izitshalo eziqhakazayo zangempela zazisekhona. Kwakunjalo nangezihlahla zokhuni oluqinile.
Ngokuqondene nezilwane, ama-dinosaurs asakazeka emhlabeni wonke ngalesi sikhathi, kuyizilwane ezazidlula emhlabeni ngesikhathi sonke esisele.
Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi ngeJurassic.