El Isikhathi se-Devonia kwakha esinye sezigaba ezinhlanu ezazinenkathi yePaleozoic. Lesi sikhathi sinezinguquko eziningi kakhulu ezingeni le-geological kanye ne-biodiversity kuyo yonke iplanethi. Kwahlala cishe iminyaka eyizigidi ezingama-56 futhi amaqembu ahlukahlukene ezilwane angakhula, ikakhulukazi lawo asendaweni yasolwandle. Kwakukhona nezinguquko ezindaweni zokuhlala izilwane zomhlaba, lapho kwavela khona izitshalo ezinkulu nezilwane zokuqala zomhlaba. I- Izilwane zase-Devonia Kwakwaziwa ukuthi kungumgibeli wamahhashi kakhulu kude kakhulu. Yize lesi sikhathi saziwa ngokuba nesiqephu sokuqothulwa lapho okungaphezulu kwama-80% ezinhlobo zanyamalala.
Ngakho-ke, sizonikezela le ndatshana ukukutshela konke odinga ukukwazi mayelana nezilwane ze-Devonia.
Ukuthuthukiswa kwezilwane zase-Devoni
Le nkathi yayiphelele ukuthuthukisa impilo. Futhi ukuthi amazinga okushisa abemnandi ngalesi sikhathi futhi avumela ukuthuthukiswa okuhle kwezilwane nezitshalo. Zonke izilwandle ezikhona kulesi sikhathi zazinezinga eliphezulu lokuphila. Futhi ukuthi olwandle lezo zinhlobo zakudala kakhulu njengezipanji zingakhula. Izinhlobo zezipanji ezinothile zaqala ukuvela futhi ngokuchuma emadwaleni ama-coral, bakwazi ukwakha ukujwayela okuhlukile. Izipanji ezinesiliceous zinokumelana okukhulu nezimo zemvelo kanye nokuba khona kwezilwane ezidlayo.
Imifula yamakhorali kanye ne-alga benthic nayo yadlala indima enkulu ekuthuthukiseni i-ocean morphology.. Itshe elikhulu libe selinwebeka izinkulungwane zamakhilomitha, lihlukanisa izwekazi lonke. Izilwane ze-Devonian zabhekana nolunye lwezinguquko ezinkulu kakhulu emvelweni yasemanzini, njengoba kwavela izilwane ze-nektonic. Eziningi zalezi zilwane ezintsha zaziyizilwane ezidla ezinye.
Lapho kunokuthuthuka okusha kohlobo noma lokuzivumelanisa nemvelo, ingcindezi itholakala kuloluchungechunge lwe-trophic. Lokho wukuthi, uma kunezilwane ezintsha ezizingela inyamazane yazo, ithuthukisa isimilo esisha ezinhlotsheni ezidinga ukubaleka ziphunyuke kulezi zimo zisaphila. Lokhu kuguqulela enkathini yokuziphendukela kwemvelo nokuzivumelanisa nezimo ezintsha ezakha ukwehluka kohlobo lwezilwane nezitshalo.
Ezinhlelweni zemvelo zasemanzini siphinde sabona ukuthuthuka kokuhlukahluka kwe-mollusc, okuholela ekubonakaleni kwama-ammonoid okuqala. Lawa ma-ammonoid avela ekuveleni kwama-nautiloid ngesikhathi sezilwane ezisezingeni eliphansi laseDevonia. Ama-nautiloid aqhubeka yize enokwehluka okuncane nobuningi.
Izilwane zasemanzini zase-Devonia
Ezindaweni ezihlala emanzini angenasawoti ama-bivalve aqala ukwanda futhi ahlasele. Ngaleso sikhathi, ama-trilobite aqala ukwehla kancane kancane, nakuba amafomu amasha empilo ayesavela. Kwakukhona ama-trilobite amakhulu. Ngakolunye uhlangothi, sasinama- eurypterid arthropods, aqhubeka eyiqembu elibaluleke kakhulu lezilwane ezidla ezinye.
Phakathi nalokhu kwanda, izilwane zasemanzini ze-Devonian zazama ukukhula kwezinhlanzi. Ikakhulukazi ama-placoderm noshaka, kokubili ama-osteichthians kanye nama-sarcopterygians, okuvela kuwo ama-vertebrate omhlaba, njengama-actinopterygians. Leli qembu lokugcina yilona okwamanje eligcwele ulwandle. Kukhona ososayensi abazi ukuthi izilwane zase-Devoni zineminyaka yobudala bezinhlanzi. Lokhu kungenxa yokuthi kukhona izinsalela zalezi zinhlanzi ezahlukahlukene kakhulu futhi ezigcinwe kahle, iningi lazo lifakwa echibini lamanzi angenasawoti.
Ama-coelacanths asevele engowosuku ngalesi sikhathi. Maphakathi ne-Devonian fauna, ama-placoderms aqala ukuthola indawo ngokumelene nama-ostracoderms. Yilokhu okudale ukuthi i-Ichthyostega ne-Acanthostega baphume ohlwini lozalo lwe-sarcopterygian. Lezi zinhlobo ezimbili zixhunywe ekuguqukeni kwezinhlanzi kuya kuma-tetrapods. Lolu shintsho lomlando lwenziwa ngesikhathi soguquko phakathi kwe-Devonian kanye ne- Isikhathi seCarboniferous.
Okunye ukungabaza okukhulu okukhona ngalezi zinhlanzi ukuthi zazingamanzi noma zasolwandle. Lokhu kungabaza kuphakama ngenxa yokuthi kuye kwatholakala izinhlanzi eziningi zasemanzini angenasawoti ematsheni esihlabathi amadala abomvu. Le ndawo isemhlabeni futhi yakhiwe ngokuvalwa kwe-Iapetus Ocean. Lesi isizathu esiyinhloko esenza kube nokungabaza ngokuthi lezi zinhlanzi zazingasemanzini ahlanzekile noma zasolwandle. Amarekhodi okuqala alezi zinhlanzi atholakala ngemidiya yasolwandle, nakuba iningi lazo bayizinhlanzi zasemanzini ezingenasawoti. Ukusuka lapho, kwavela amaqembu ahlukahlukene ezinhlanzi.
Ukwenziwa amakoloni komhlaba
Esinye isici esiyinhloko esenza i-Devonian fauna igqame ukubuthwa komhlaba. Ngesikhathi se- Isikhathi se-Silurian, cishe ama-arthropods ahlasela izwe. Kodwa-ke, idatha yokuqala ivela ku-Lower Devonian Rhynie Chert Formation yaseScotland. Lolu lwazi lugcina wonke umphakathi wezitshalo nama-arthropods anikeze ingcebo yolwazi mayelana nemvelo yakudala yezindawo zakuqala zomhlaba.
Kunezinhlobo eziningi zezitshalo ezisize i-arthropods, kufaka phakathi ofezela, izibungu nezinambuzane ezinamaphiko, ukuthuthukisa futhi kube nohlelo olufanele lwemvelo. Ama-arthropods asolwandle namanzi ahlanzekile kudingeke ukuthi iguquke ezinhlelweni zomhlaba ngenxa yokuthuthuka kokuphefumula komoya. Kodwa-ke, kunzima ukuthola ngedatha erekhodiwe yezinsalela ezimbiwa phansi ukuthi sinokubala okunembe kakhudlwana kokuhleleka lapho izimbuzane, ofezela, nama-centipede afika khona ku-ecosystem yasemhlabeni. Wonke lawa ma-arthropods namuhla anenzalo ehluke ngokungavamile eye yajwayela izimo zemvelo ezihlukahlukene kakhulu, ngenxa yokuthuthukiswa kwezitshalo zemithambo.
Ngaphambi kokuvela kwezilwane ezinomgogodla, wonke umhlaba wakudala wawugcwele ama-arthropods. Kunempikiswano ethile esaqhubeka nokusabalala emhlabeni wonke wesayensi mayelana nesikhathi lapho izilwane ezinomgogodla ziphuma emanzini kanye nezizathu eziholele ekutheni zenze kanjalo. Kumelwe kuvunywe ukuthi kunzima ukucabanga ukuthi isilwane esihlala endaweni ezungezile yasolwandle singagcina sesijwayele ukujwayela indawo esingazange siphile kuyo futhi esingadingi ukuphila kuyo.
Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi ngezilwane ze-Devonia.