El Lokacin Devonian kafa ɗaya daga cikin ƙananan rarrabuwar biyar waɗanda suke da zamanin Paleozoic. Wannan lokacin yana da canje-canje masu yawa a matakin ilimin ƙasa da bambancin halittu a duk faɗin duniya. Ya ɗauki kimanin shekaru miliyan 56 kuma ƙungiyoyin dabbobi daban-daban na iya haɓaka, musamman waɗanda ke cikin mazaunin ruwa. Hakanan akwai canje-canje a mazaunan dabbobin ƙasar, inda manyan tsirrai da dabbobin ƙasar na farko suma suka bayyana. Da Dabbobin Devonian An san shi da cewa ya fi kowa doki nesa. Kodayake ana yin la'akari da wannan lokacin don samun yanayin ɓarna inda sama da 80% na jinsunan suka ɓace.
Saboda haka, zamu sadaukar da wannan labarin don gaya muku duk abin da kuke buƙatar sani game da fa'idodin Devonian.
Ci gaban fauna na Devonian
Wannan lokacin ya kasance cikakke don haɓaka rayuwa. Kuma shine yanayin zafi ya kasance mafi daɗi a wannan lokacin kuma ya ba da kyakkyawan ci gaba na fauna da flora. Duk tekun da ke cikin wannan lokacin yana da kyakkyawan yanayin rayuwa. Kuma shine a cikin tekun wadancan mafi dadadden nau'ikan halittu kamar su soso zasu iya bunkasa. Nau'o'in soso na siliceous sun fara bayyana kuma ta hanyar bunkasa akan murjani, sun sami damar haɓaka abubuwa daban-daban. Sponges na silice suna da tsayayyar juriya ga yanayin muhalli da kasancewar masu farauta.
Coral reefs da benthic algae suma sun taka muhimmiyar rawa wajen haɓaka ilimin halittar teku.. Babban gaci da aka faɗa a wancan lokacin daga nisan dubban kilomita wanda ya iyakance wata nahiya. Dabbobin Devonian suna da ɗayan manyan canje-canje a cikin halittun cikin ruwa kamar yadda dabbobi nektonic suka bayyana. Yawancin waɗannan sabbin nau'in dabbobin sun kasance masu farauta.
Lokacin da akwai wani sabon ci gaba na jinsi ko dacewa da muhalli, ana matsa lamba akan sarkar trophic. Wato, idan akwai wasu sabbin dabbobin da ke farautar abincinsu, to yana inganta sabon hali a cikin jinsunan da ke bukatar guduwa da kubuta daga wadannan halaye da rai. Wannan yana fassara zuwa lokacin juyin halitta da dacewa da sabbin yanayi wanda ke haifar da yaduwar halittar dabbobi da tsirrai.
A cikin yanayin halittar cikin ruwa kuma muna nuna ci gaban da yawaitar mollusks wanda ke haifar da ammonoids na farko da suka bayyana. Wadannan ammonoids sun fito ne daga juyin halittar nautiloids a lokacin fauna na Lowerananan Devonian. Nautiloids sun ci gaba kodayake tare da karancin bambancin da yawa.
Dabbobin ruwa na Devonian na ruwa
A cikin wuraren zama na ruwa, bivalves ya fara yaduwa da mamayewa. A waccan lokacin trilobites sun fara raguwa kadan kadan kodayake sabbin sifofin rayuwa suna bayyana. Akwai wasu manyan trilobites. A gefe guda, muna da cututtukan cututtukan eurypterid, wanda ya ci gaba da kasancewa muhimmiyar ƙungiyar mafarauta.
Yayin wannan fadada dabbobin ruwa na Devonian suna da gwaji game da haɓakar kifi. Musamman ya kasance placoderms da sharks, duka osteichthians da sarcopterygians, daga abin da aka samo asalin halittar ƙasa, kamar su actinopterygians. Wannan rukuni na ƙarshe sune waɗanda a halin yanzu suka fi yawa a cikin teku. Akwai masana kimiyya waɗanda suka san faunan Devonian kamar shekarun kifi. Wannan ya faru ne saboda akwai dadaddu masu yawa da kuma adana dadaddun burbushin wadannan kifaye, dayawa daga cikinsu a tafkunan ruwa mai kyau.
A wannan lokacin coelacanth sun riga sun dace. A tsakiyar fauna na Devonian placoderms sun fara ƙarancin ostracoderms. Waɗannan abin da ya sa Ichthyostega da Acanthostega suka tashi daga zuriyar sarcopterygian. Wadannan jinsin biyu suna da nasaba da sauyawar kifi zuwa tetrapods. Anyi wannan canjin tarihin ne yayin canji tsakanin fauna na Devonian da Lokacin Carboniferous.
Ofaya daga cikin manyan shakku game da waɗannan kifaye shine cewa sun kasance ruwan ɗumi ko na ruwa. Wannan shakku ya samo asali ne daga gaskiyar cewa an sami kifin da yawa a cikin tsohuwar tsohuwar sand sands. Wannan yanki yanki ne na kasa kuma an kirkireshi ne ta hanyar rufe tekun Iapetus. Wannan shine babban dalilin shakku kuma waɗannan kifaye sun kasance ruwa ne na ruwa ko na ruwa. Rikodi na farko da aka ba waɗannan kifayen ana samun su ne ta hanyoyin ruwa, kodayake mafi yawansu su ne kifin ruwan siluriyan ruwa. Daga nan ne, kungiyoyin kifaye daban-daban suka bullo.
Mulkin mallaka
Wani babban halayyar da ke haifar da fauna ta Devonian shine ficewar ƙasar. Yayin Lokacin Silurian arthropods tabbas sun mamaye ƙasar. Koyaya, bayanan farko sun fito ne daga samuwar Devananan Devonian Rhynie Chert na Scotland. Wannan bayanin ya ƙunshi dukkanin tsire-tsire da tsire-tsire waɗanda suka ba da babban bayani game da ƙarancin yanayin ƙasa na farkon yanayin duniya.
Akwai nau'o'in tsire-tsire masu yawa waɗanda suka taimaka maƙalar kwalliya, gami da kunama, mites, da ƙwari masu fuka-fuka, don haɓaka da samun yanayin halittu masu dacewa. Tsarin ruwa da na ruwa mai tsafta dole ne ya canza zuwa tsarin duniya saboda ci gaban numfashin iska. Koyaya, yana da wuya a kafa tare da bayanan bayanan burbushin cewa akwai mafi ƙidayar ƙidaya akan umarnin isowar kwari, kunamai da ɗakuna biyu zuwa yanayin yanayin ƙasa. Duk waɗannan tsararru a yau suna da zuriya iri-iri daban-daban kuma an daidaita su da yanayin muhalli daban-daban saboda godiya ga ci gaban shuke-shuke.
Kafin bayyanar kashin baya, duk duniyar da ta gabata ta kasance mutane ne da yawa. Akwai wata takaddama da ke ci gaba da yaduwa a duniyar kimiyya kuma tana magana ne game da lokacin da gangarowa suka yunkuro daga ruwa da kuma dalilan da suka ingiza su yin hakan. Dole ne a yarda cewa yana da wuya a yi tunanin cewa dabbar da ke da yanayin halittar ruwa ya ƙare da haɓaka yanayin yanayin da ba ya rayuwa a ciki kuma baya buƙatar rayuwa.
Ina fatan cewa tare da wannan bayanin zaku iya koyo game da fauna na Devonian.