Lokacin Devonian

Zamanin Paleozoic yana da ƙananan rarrabuwa guda 5 da aka raba su zuwa lokaci wanda aukuwa daban-daban masu girma na ilimin ƙirar halitta da ƙasa suka faru. Yau zamuyi magana akansa Lokacin Devonian. Wannan lokacin ya ɗauki kimanin shekaru miliyan 56 wanda duniyarmu ta sami canje-canje da yawa, musamman ma a matakin bambancin halittu, har ma a matakin ilimin ƙasa.

A cikin wannan labarin zamu maida hankali kan gaya muku halaye, yanayi, yanayin kasa, fure da fauna na zamanin Devonian.

Babban fasali

Wannan lokacin ya fara kimanin shekaru miliyan 416 da suka gabata kuma ya ƙare kimanin shekaru miliyan 359 da suka gabata. Kamar koyaushe, dole ne muyi sharhi cewa farkon da ƙarshen zamani ba haka suke ba saboda rashin irin wannan cikakken bayanin. Wannan shine lokaci na huɗu na zamanin Paleozoic. Bayan lokacin Devonian yazo lokacin carboniferous.

A wannan lokacin an sami ci gaba mai tarin yawa na rukunin dabbobi daban-daban, musamman waɗanda ke zaune a yankunan ruwa. Hakanan akwai canje-canje masu mahimmanci a cikin mazaunan ƙasa kamar yadda manyan tsirrai da dabbobin farko na ƙasa suka bayyana. Duk da cewa lokaci ne wanda rayuwa take ta bunkasuwa a matakai daban-daban, Devonian kuma yana da kyakkyawan suna kamar lokacin da yawancin dabbobin dabbobi suka bace. Akwai magana game da kusan ko theasa game da 80% na rayuwa a duniyarmu.

A wannan lokacin, wani al'amari na bacewa mai yawa wanda ya sanya yawancin jinsunan da suke rayuwa a wancan lokacin sun bace daga doron duniya har abada. A lokaci guda da muke da zamanin Devonian, ya kasu kashi daban-daban. Bari mu ga menene waɗannan lokutan:

• Devananan Devonian. An ƙirƙira shi bi da bi ta shekaru 3 da ake kira Lochkovian, Pragian da Emsian.
• Middle Devonian: shekaru biyu da ake kira Eifelian da Givetian
• Babban Devonian: an kafa ta da birane biyu da ake kira Frasniense da Fameniense.

A ƙarshen wannan lokacin, ɗayan al'amuran ɓarkewar ɗumbin duniya ya faru wanda ya haifar da asara mai yawa na jinsi, galibi waɗanda ke zaune a tekun ɓangaren wurare masu zafi. Jinsunan da abin ya fi shafa sun kasance murjani, kifi, crustaceans, mollusks, da sauransu. Abin farin ciki, yawancin jinsunan da ke rayuwa a cikin halittu masu rai na duniya basu shafi abin da ya faru na yawan hallaka su ba. Saboda haka, mamayar mazaunin ƙasa na iya ci gaba da aikinta ba tare da matsaloli da yawa ba.

Ilimin ƙasa na Devonian

Wannan lokacin yana alama da babban aiki na faranti na tectonic. Akwai abubuwan taɓawa da yawa waɗanda suka kafa sabbin manyan ƙasashe kamar samuwar Laurasia. Hakanan an ƙirƙira kuma aka kiyaye babban yankin da aka sani da sunan Gondwana. Babban yanki ne wanda ya mamaye dukkan sararin samaniya a kudu.. Siberia da babban Tekun Panthalassa sun mamaye arewacin duniya. Dukan tekun ya rufe kusan duka arewacin duniya.

Daga mahangar orogeny, wannan wani zamani ne wanda aka fara aiwatar da tsari daban-daban na kirkirar tsaunukan tsaunika, daga ciki muke da Dutsen Appalachian.

Yanayin lokacin Devonian

Yanayin canjin yanayin da ya wanzu a duniyarmu a lokacin zamanin Devonian ya kasance mai kwanciyar hankali. Mafi rinjayen yanayin duniya yayi zafi da danshi tare da wadataccen ruwan sama. Koyaya, yanayin busasshe da bushe sun wanzu a tsakanin manyan nahiyoyin nahiyoyi.

Matsakaicin yanayin zafin duniya yana kusan digiri 30. Yayin da lokaci ya ci gaba, an sami raguwar ci gaba kaɗan, ya kai kimanin digiri 25. Daga baya a ƙarshen zamanin Devonian, yanayin zafi ya ragu har ya zuwa ɗaya daga cikin ƙyalli wanda ya canza duniyarmu cikin tarihi.

vida

A wannan lokacin akwai canje-canje masu mahimmanci dangane da rayayyun halittu. Ofayan ɗayan waɗannan canje-canjen mafi mahimmanci shine tabbatacciyar mamayar yanayin ƙasa. Bari mu fara nazarin flora.

Flora

A zamanin pre-Devonian, ƙananan ƙwayoyin cuta kamar fern sun riga sun fara haɓaka. Waɗannan ƙananan fern sun sami ci gaba mafi girma a fannoni daban-daban, mafi wakiltar su shine girman su. Sauran siffofin shuke-shuke suma sun bayyana a saman nahiyoyin, kamar su lycopodiophytes. Akwai wasu nau'in tsirrai wadanda basu iya daidaitawa da yanayin muhalli ba kuma suka kare da bacewa.

Yawaitar tsirrai na kasa ya kawo sakamakon karuwar iskar oxygen wanda ya kasance a cikin sararin samaniya tun tsire-tsire sun aiwatar da aikin photosynthesis albarkacin launin fata na chlorophyll. Godiya ga wannan, ya fi sauƙi ga rayuwar ƙasa ta yaɗu ta hanyoyin halittu na ƙasa.

fauna

Aƙarshe, fauna ya banbanta sosai a zamanin Devonian farawa da kifi. Oneaya ce daga cikin ƙungiyoyin da suka sami babban ci gaba a matakin yawan jama'a. Dayawa suna kiran wannan zamanin da shekarun kifi. Jinsuna kamar su Sarcopterygians, Actinopterygii, Ostracoderms da Selacians.

Dalilan da suka salwanta zamanin Devonian

Kamar yadda muka ambata a baya, a ƙarshen wannan lokacin aiwatar da ɓarkewar taro. Ya fi shafar rayuwar halittun tekuna. Thearshen ya ƙare kusan shekaru miliyan 3. Abubuwan da suka haddasa wannan halaka ta mutane sune:

• Meteors
• Raguwar mahimmanci a cikin matakan oxygen a cikin tekuna
• Dumamar yanayi
• Shuka girma ko taro
• M volcanic aiki

Daga cikin dalilan da muka kawo akwai yiwuwar shakku game da ci gaban tsirrai. A wannan lokacin, manyan tsire-tsire masu jijiyoyin jiki sun haɓaka, kasancewa matsakaita ya kai kimanin mita 30 a saman nahiyoyin. Wannan yana da mummunan sakamako haifar da rashin daidaituwa a cikin yanayin muhalli, tunda waɗannan tsirrai zasu fara shan ruwa da abubuwan gina jiki daga ƙasa waɗanda wasu rayayyun halittu zasu iya amfani dasu. Wannan ya haifar da asarar halittu masu yawa.

Ina fatan cewa tare da wannan bayanin zaku iya koyo game da zamanin Devonian.