La Oligocene nguva yaive yechitatu uye yekupedzisira yenguva dzakaumba nguva yePaleogene yenguva ye Cenozoic. Iyo inguva yenguva iyo nyika yakaona kana inoonekwa shanduko padanho rezvinhu zvipenyu uye geology. Iyo Oligocene fauna yakakwanisa kubudirira nekutenda kushanduko yakakosha mumamiriro ekunze iyo yakagadzira mamiriro akakodzera kuti mhuka nemiti zvikure.
Muchikamu chino tichaudza iwe nezve zvese hunhu uye shanduko yemhuka yeOligocene.
Oligocene nguva
Iyi nguva yakatanga kusvika makore angangoita mamirioni makumi matatu nemana uye akapera angangoita makore zviuru makumi maviri nezvitatu apfuura Munguva yese iyi nyika yakaita shanduko dzinooneka. Mamiriro ekunze akaitisa basa rakakosha mukusimudzira mbeu nemhuka. Shanduko idzi mupasi dzakakonzera kuti mhuka dzifanirwe kuzviparadzira patsva pasi.
Iyo Oligocene yave iri nguva yakanakidza mazvikokota mukudzidza kweiyo geological nguva sezvo ivo vakatsaura yakakwana nguva uye kuyedza kujekesa zvakavanzika zvakanyanya. Nguva yeOligocene ingangoita mamirioni gumi nemana emakore uye, panguva ino, mafambiro ematetoni mahwendefa akaenderera mberi, achisvika pazvinzvimbo zvakafanana neizvo zvavainazvo nhasi.
Mhuka dzeOligocene dzinozivikanwa nekuzivikanwa sezera rezvipuka. Uye ndezvekuti iro boka rezvipuka rakange riri iro rakasangana nekusiyana kukuru uye kusiana panguva iyi. Nekuda kwekusimudzira uye kuwedzerwa kwemhuka, zvidimbu zvinozivikanwa senge makonzo uye canid zvinogona kugadzirwa. Izvo zvinonyanya kumira zvakanyanya kubva ku geology yenguva ino ndeye Laramide orogeny uye Alpine orogeny.
Kana iri mamiriro ekunze, mamiriro akasarudzika panguva iyi aive akanyanyisa. Yakanga ichiratidzwa netembiricha yakaderera kwazvo umo matanda acho akaramba akavharwa nechando. Dzimwe ecosystem dzakashandurwa nekuderera kwetembiricha yepasirese. Ngationgororei hupenyu zvirinani.
Flora
Miti yeOligocene inoratidzirwa zvakanyanya nemasango eeconiferous ayo akaunganidzwa pamwe nemasango anodonha. Masango aya akagadzirirwa kuti akwanise kurarama pakadzika tembiricha. Angiosperms yakatanga kupararira kune huwandu hwenzvimbo dzekugara, kuwana kuva nehukuru hwesimba.
Nekuda kwekutonhora kwemamiriro ekunze, kuderera kwemasango enzvimbo dzinopisa kunogona kucherechedzwa, kwakatsiviwa nemiti inomera uye huswa. Mhando dzakasiyana dzezvirimwa dzaifanira kutarisana nekuita kwemafuro emhuka dzinoafudza. Ngationgororei kuti mhuka idzi chii.
Oligocene fauna
Mhuka dzeOligocene dzinozivikanwa nekuve nemapoka mazhinji emhuka dzakakwanisa kusiyanisa nekubudirira kunyangwe mamiriro ekunze avakawanikwa. Mune aya mapoka akasiyana emhuka tinowana shiri, zvinokambaira uye zvipuka. Mamwe masayendisiti anonzi maOligocene fauna zera rezvipuka. Iyo ingangoita panguva yenguva yeCenozoic chii chimwe chinogona kuwedzera maererano nezinyama.
Huwandu hukuru hwemhando nyowani dzemhuka dzakabuda, pakati padzo tine makonzo, canids, primates uye cetaceans. Tichaongorora imwe neimwe yadzo.
Makonzo
Mukati mehurongwa hwemakonzo tinowana iro rakazara boka rezvipuka rakasimukira panguva yemhuka dzeOligocene. Hunhu hwayo hwakabatsira kuvasiyanisa kubva kune vamwe vese aive akanyanya kupinza mazino ane mashandisiro akawanda. Imwe yacho ndeyekuruma zvikara kana kutsenga huni. Iyo inonyanyo kuzivikanwa mhuri yeOligocene yemakonzo yaive iyo Eomyidae. Dzakanga dzakafanana nesikiri yanhasi asi dziine muviri mudiki uye tsika dzekuzvara.
Primates
Ivo iboka rezvipuka zvinozivikanwa nekuve neminwe mishanu panhengo. Imwe yemabhenefiti epamusoro pemhuka idzi pamusoro pezvimwe zvipfuyo chigunwe chinopesana. Pamusoro pezvo, vane tsoka dzakasimwa dzinobvumidza iwo wese mutsoka kutsigirwa kuti ufambe. Maitiro ayo emazino akajairwa uye haana kunyanya kunyatso shanda. Iwo ma primates anogona kucherechedzwa kazhinji panguva ino aive maremur uye tarsier.
Iyo tarsier ihama yemurume ine diki saizi ingangoita gumi masendimita. Hunhu hwavo hukuru ndewekuti vane maziso mahombe anovabvumira kuchinjisa chiono chavo murima. Ivo vakazara kudya paiyo nyoka uye vanopedza yavo yakawanda nguva yakaturikwa mumatavi emiti.
Kune rumwe rutivi, iyo lemur ndeye primate iyo inogona kusiyanisa saizi zvichienderana nes subspecies. Chimwe chehunhu hunomira muswe wayo murefu. Muswe uyu unowanzoreba kupfuura muviri wakazara. Maziso avo akakura uye anovabvumira kuti vaone rima. Ivo havana kusiyanisa mavara zvakanaka kunyangwe ivo vachigona kusiyanisa maumbirwo.
Oligocene fauna: canids
Mukati me canids ivo vari veboka remhumhi nembwa. Hunhu hwayo hukuru kuve nemuviri uri pakati nepakati uye kufamba kuchitsigirwa pamazano eminwe. Ivo chikafu chinodya uye vazhinji vacho zvikara. Ivo vakaonekwa muEocene uye gare gare vakasiyana.
Cetaceans
Boka rezvipuka rakakwanisa kugadzirisa zvakanyanya kune hupenyu hwemumvura. Hunhu hwayo hukuru ndeyemberi kwembambo dzakashandurwa kuti dzikwanise kuve zvimbi. Hembe dzadzo hadzi dzakanyangarika nekufamba kwenguva. Kufema kwavo ipurmonary, saka vanofanirwa kukwira kumusoro kumusoro kuti vatore mhepo.
Munguva yeOligocene fauna imwe yemhuka huru dzenyika dzakagadzirwa. Inozivikanwa seParaceratherium. Yaive nezviyero zvekufungidzira zve angangoita 8 mita kukwirira uye 7 mita kureba. Idzo dzaive mhuka dzinodya zvipuka zvine hunhu hwakanyatso kukura hwekunhuwa. Izvo zvaive zvisingafambidzane zvachose, asi vaive nehupenyu hwekusurukirwa. Sezvineiwo ivo vairwisana, vachirovana misoro yavo uye vakaita kuti vadzivirirwe nemapfupa ehenya zvakanyanya kupfuura zvakajairwa.
Ndinovimba kuti neruzivo urwu unogona kudzidza zvakawanda nezve iyo Oligocene fauna.