Isikhathi se- I-Pleistocene kwaba isigaba sokuqala sokuma komhlaba se Isikhathi se-Quaternary. Kwakubonakala ikakhulukazi ngamazinga okushisa aphansi amboza cishe yonke iplanethi ngeqhwa. I- Izilwane zePleistocene kwakubonakala ikakhulu ngokuvela kwezilwane ezinkulu ezincelisayo ezifana nesilwane esincelisayo. Siphinde sibheke kule nkathi yesikhathi ukuvela kohlobo lomuntu. Kungalesi sikhathi lapho kwavela khona okhokho bendoda yesimanje.
Kule ndatshana sizohlaziya zonke izici nokuvela kwezilwane zasePleistocene.
Umongo ojwayelekile wezilwane zasePleistocene
Ukuqonda ukukhula kwezilwane zasePleistocene, kufanele siqonde umongo ojwayelekile, kokubili isimo sezulu kanye nokwakheka komhlaba, njll. Isikhathi esingesinye sezifundwe kakhulu futhi esinamarekhodi ezimbiwa phansi kakhulu. Ngalesi sizathu, kube ngesinye sezikhathi lapho kunemininingwane ebanzi futhi ethembekile. Le nkathi yesikhathi yaqala Eminyakeni eyizigidi ezingama-2.6 edlule futhi yaphela ngemuva kweminyaka yokugcina yeqhwa, cishe i-10.000 BC
Sonke lesi sikhathi, izilwane ezinkulu ezincelisayo zazinobuhle bazo obukhulu, maqondana nentuthuko nokwehlukahlukana. Phakathi kwazo kukhona i-mammoth, i-megatherium kanye nama-mastonon abusa cishe yonke iplanethi. Isici esenza zihluke kwezinye izilwane kwakungusayizi wazo omkhulu. Kuyadingeka futhi ukuphawula ngokuthuthuka kokhokho bomuntu njengo IHomo erectus, iHomo habilis, neHomo neanderthalensis.
Mayelana nokwakheka komhlaba, sithole ukuthi kuncane ukufuduka kwamazwekazi. Kulokhu, ukukhukhuleka kwezwekazi bekuphansi impela futhi bekuqhubeka kunjalo kusukela lapho. Kakade ngalesi sikhathi amazwekazi ayenezikhundla ezifanayo nanamuhla. Ukuhlaziya isimo sezulu siyabona ukuthi bekukhona ukubanda kwamazinga okushisa aphansi. Futhi ukuthi ngalesi sikhathi kwenzeke imijikelezo eminingi yeqhwa. Kwahlala kunje ngaso sonke isikhathi kwaze kwaphela iminyaka yokugcina yeqhwa. Ingxenye enkulu yeplanethi yayimbozwe yiqhwa. Ochwepheshe babhale ukuthi cishe u-30% womhlaba wonke wawuqandekile. Isigxobo esiseningizimu e-Antarctica sasimbozwe ngokuphelele yiqhwa njenganamuhla. Wonke amazwe e-Arctic Circle nawo ayekhona.
Lapho sesihlaziye umongo walesi sikhathi, siqala ukuhlaziya izilwane zasePleistocene.
Izilwane zePleistocene
Ngalesi sikhathi kwakuyizilwane ezincelisayo ezaba iqembu elibusayo. Gcina okuhlanganisiwe konke ukukhathazeka okuqale ezikhathini ezedlule. Ezilwaneni zePleistocene, ukuvela kwalokho okubizwa nge-megafauna kugqamile. Le megafauna isho izilwane ezinkulu ezazikwazi ukumelana namazinga okushisa aphansi ayekhona ngaleso sikhathi.
Yize izilwane ezincelisayo bekungukuthuthuka okuphezulu nokuhlukahluka kwezilwane zalesi sikhathi, amanye amaqembu ezilwane ezinjengezinyoni, izilwane eziphila ezweni nasemanzini nezilwane ezihuquzelayo nawo aqhubeka ukwehluka. Iningi lala maqembu ezilwane asekhona kuze kube namuhla. Kodwa-ke, akunakuphikiswa ukuthi izilwane ezincelisayo kwakungamakhosi alo nyaka.
I-Pleistocene megafauna yayinezilwane ezinkulu kakhulu. Phakathi kwalezi zilwane sigcizelela abamele kakhulu i-mammoth, i-megatherium, i-smilodon, i-elasmotherium, phakathi kwabanye. Sizohlaziya ngazinye izilwane eziyinhloko zezilwane zasePleistocene.
omkhulukazi
Lezi zilwane kwakungezohlobo lweMammuthus futhi zazibukeka zifana nezindlovu esinazo namuhla. Esinye sezici ezimelele kakhulu zaleli qembu ukwandiswa kwalo ngamakhala. Lokhu kungenxa yokuthi bangabaka-oda be-Proboscidea futhi banesitho esaziwa ngesiqu njengesiqu. Igama layo lesayensi yi-proboscis. Omammoths nabo babephethe amazinyo amade, abukhali asize ukuzivikela ezilwaneni ezingabahlasela. Lezi fangs zazinokugoba okubabhekise phezulu. Lezi zimpondo zazenziwe ngezinyo lendlovu.
Ngokuya ngendawo okwabiwa ngayo umuntu nokusondela noma ukude kwezindawo ezinamazinga okushisa aphansi, umzimba wawumbozwa ngoboya obuningi noma obuncane. Umkhuba wayo noma ukudla kwayo kwakungukudla okumnandi. Lokhu kwenza amazinyo abe nomsebenzi wokuzivikela kuphela. Naphezu kokubonakala kwayo okukhulu futhi kungokwesigaba sePleistocene megafauna, yanyamalala kule nkathi elandelayo. Ngenxa yamarekhodi amaningi wezinsalela zakudala, kuye kwenzeka ukwazi okuningi nge-morphology nendlela yokuphila yalesi silwane.
I-Megatherium
Lezi zilwane zingaphansi kwe-oda lePilosa futhi zihlobene nama-sloths amanje. Luhlobo lwesilwane esaba esinye sezilwane ezinkulu kakhulu emhlabeni. Isisindo sakhe esilinganisiwe sasingu phakathi kwamathani ayi-2.5 no-3 futhi cishe ayemamitha ayi-6 ubude. Lolu hlobo lucwaningwe ngenxa yezinsalela eziqoqiwe. Amathambo ayo ayeqinile impela, ngakho kusolwa ukuthi kwakudingeka asekele inqwaba yenyama.
Njengama-sloths namuhla, ayenezinzipho ezinde kakhulu. Lezi zinzipho zazisetshenziswa ikakhulu ukumba ukudla. Ukudla kwabo bekukunyoka ngokuphelele futhi kucatshangwa ukuthi babeziphethe bodwa. Umzimba wawumbozwe ngoboya obukhulu obusiza ukuwuvikela emazingeni okushisa aphansi ayekhona ngalezo zikhathi. Indawo yokuhlala kanye nendawo okwabiwa kuyo yanwetshwa yizindawo zaseNingizimu Melika.
I-Smilodon
Lesi silwane esomndeni wakwaFelidae, ngokuba izihlobo eziqondile zezinsikazi ezikhona manje. Isici saso esiyinhloko kwakuwusayizi wayo omkhulu namazinyo amabili amade aphuma emihlathini yawo engenhla. Ngenxa yalezi zici i-smilodon yayaziwa emhlabeni wonke njenge »Amahlosi anamazinyo amaSaber». Ingesinye sezilwane ezifundwa kakhulu kuwo wonke umlando ngoba futhi ikhona ezindabeni eziningi nasezinganekwaneni.
Ngenxa yezinsalela eziqoqiwe ezivela kulezi zinhlobo, abesilisa bangafinyelela kumakhilogremu angama-300 ngesisindo. Babehlala ikakhulukazi kuzo zonke izindawo eziseNyakatho naseNingizimu Melika.
I-Elasmotherium
Kwakungesinye sezilwane ezincelisayo ezazingezomndeni wakwaRhinocerotidae, ezihlobene nobhejane banamuhla. Isici esivelele salezi zilwane ukuthi zazinophondo olukhulu olwaphuma kugebhezi lwazo futhi olwalungafinyelela ngaphezu kwamamitha amabili. Ukudla kwabo kwakudla imifino kanti ukudla kwabo okuyinhloko kwakungotshani.. Njengakwezinye izilwane ezincelisayo zasePleistocene, yayinomzimba ovalwe ngoboya obukhulu. Indawo ehlala kuyo nendawo okwabiwa kuyo yayisezindaweni ezisenkabeni ye-Asia kanye namathafa aseRussia.
Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi ngezilwane zePleistocene.