Ucwaningo lwakamuva lubonise ukuthi izitshalo eziqhakazayo zavela ngaphambi kwesikhathi kakhulu kunalokho okwakucatshangwa ngaphambili. Ukubukeka kwayo kutholakala esikhathini se-Triassic, eminyakeni engaphezu kwezigidi ezingu-250 edlule.
Lokhu ukutholakala okumangazayo, njengoba izitshalo eziqhakazayo zikhonjisiwe ukuthi zivele eminyakeni eyizigidi eziyi-100 ngaphambili kunalokho okukholelwa phambilini.
Izitshalo eziqhakaza izimbali zavela ezitshalweni esizazi namuhla njengama-conifers, ama-seeded ferns, ama-cycads, noma i-Ginkgo, uhlobo lohlobo lwazo kuphela. Ginkgo biloba, kodwa ukuthi ngenkathi ye-Triassic yayinezinhlobo eziningi.
Izimbali ukujwayela okwakhula njengoba izilwane ezahlukahlukene, kufaka phakathi izinambuzane, zavela futhi zavela. Ukuvela kwezitshalo eziqhakazayo nezilwane kwenzeka cishe esikhathini esifanayo, njengoba izitshalo zidinga izinambuzane ezithutha impova ukuze zivundise imbewu yazo futhi zisakaze izinhlobo zazo, nezinambuzane zidinga umpe noma impova, kuya ngokuthi imbali ikuphi, noma amakha, ukuze iphile noma ikwazi ukuzala ngokuthola umlingani.
Ingxenye yembali ethambisa kalula kakhulu impova, ingcono kakhulu kunamaqabunga noma iziqu. Ukulandelana okungaphuliwe kwempova yezinsalela kwaqala cishe eminyakeni eyizigidi eziyi-140 edlule, futhi ochwepheshe babheka ukuthi izimbali zaqala ukuvela eMhlabeni ngaleso sikhathi, ngesikhathi se-Early Cretaceous. Ngemuva kwalokhu kutholakala okusha, ukubukeka kwayo kutholakala eTriassic, eminyakeni engaphezu kwezigidi ezingama-250 edlule.
Ochwepheshe abaningi bake bazama ngaphambili ukuthola ukuthi izitshalo zezimbali zineminyaka emingaki ngokusebenzisa izifundo zamangqamuzana. Kodwa-ke, kuze kube yilapho kwenziwa lolu cwaningo olusha ngezinsalela lapho bekwazile ukusondela eminyakeni yobudala efanele yalezi zitshalo.
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