isihlobo somkhomo nehlengethwa

• izilwane zasolwandle ezidla izinyamazane ezinhlobonhlobo zohlobo lwehlengethwa

• isilwane esikhulu esidla inyama yezilwane zasolwandle edla ubhedu

• izinhlanzi ezihweba ezihlala emanzini acwebile ase-Afrika, eningizimu naseMpumalanga Asia

• izinhlanzi ezingena ngaphansi kwe-catfish

• dolphin ngombala penguin

• "insangu" ekamu lamahlengethwa

• isilwane esiseduze kakhulu esolwandle

• Isiphi isilo esikhulu kunazo zonke futhi esindayo?

• isilwane sasolwandle somndeni wamahlengethwa, umphangi

• dolphin elikhulu kunawo wonke

• Ifana nehlengethwa ejwayelekile

• Elikhulu kunawo wonke amahlengethwa

• UWilly ovela kumamuvi

• i-cetacean izilwane ezincelisayo

• Ihlengesi elikhulu kunawo wonke

• Izilwane ezincelisayo zasemanzini zasolwandle ezinamahlengethwa

Okhokho baseCetacean

Imibono yendabuko ngokuvela kwama-cetaceans yayihlanganisa iqiniso lokuthi izihlobo zabo eziseduzane futhi mhlawumbe namadlozi kwakungu-mezzanine - iqembu elaliqothuka labangadliwayo elalingafani nezimpisi ezinamaqhubu esikhundleni sezimpuphu futhi zaziyiqembu lodade abangama-artiodactyls. Lezi zilwane zazinamazinyo wesimo esijwayelekile sokukhanya, esifana namazinyo e-cetacean. Ikakhulu, ngenxa yalokhu, ososayensi kade bakholwa ukuthi ama-cetaceans avela ku-mesonichia ethile yokhokho. Kodwa-ke, idatha entsha yezakhi zofuzo ibonisa ukuthi ama-cetaceans ayizihlobo eziseduze zama-artiodactyls, ikakhulukazi imvubu. Ngokususelwa kule mininingwane, kuhlongozwa nokuthi kufakwe ama-artiodactyls ngokulandelana kwezilwane ezigudle insimbi futhi igama elithi Cetartiodactyla lihlongozelwe itekisi elinomfanekiso ofaka la maqembu amabili. Kodwa-ke, ubudala obukhulu kunabo bonke bezimvubelo ezaziwayo ze-anthracoterium, amadlozi wemvubu, iminyaka eyizigidi ezimbalwa ingaphansi kweminyaka kaPakitset, ukhokho whale owaziwa kakhulu whale.

Ukutholwa kwakamuva kohlobo I-Pacicetus, njenge-protokite-endala endala kakhulu, iqinisekisa idatha yamaseli. Isakhiwo se-Skeleton paciteta kukhombisa ukuthi imikhomo akuyona inzalo eqondile yama-mesonichids. Ngokuphambene nalokho, okhokho bomkhomo abahlukaniswe ama-artiodactyls bashintshela endleleni yokuphila yasemanzini ngemuva kokuba ama-artiodactyls ngokwawo ehlukanisiwe nokhokho abavamile nge-mesonichids. Ngakho-ke, izinhlobo zohlobo lwe-protokite kwakuyizindlela zokuqala ze-artiodactyls, ezazigcina ezinye zezici ezikhona ze-mesonichids (ukuma okwakhiwe ngamazinyo) okulahlekelwe ama-artiodactyls anamuhla. Kuyathakazelisa ukuthi okhokho bokuqala bazo zonke izilwane ezincelisayo ezingamhloniphi mhlawumbe babeyingxenye yenyama noma izikebhe.

Amahlengethwa nemikhomo kwehluka kanjani kunhlanzi futhi kungani zibhekwa njengezilwane ezincelisayo?

Okokuqala, lezi zidalwa zinegazi elifudumele. Ezinhlanzini, izinga lokushisa aliphezulu kunamazinga okushisa wamanzi, kanti emihosheni nasemidobeni, izinga lokushisa lomzimba liphezulu, kanti nendawo enkulu enamafutha, esatshalaliswa ngomzimba wonke, iyabavikela emanzini abandayo.

Amahlengethwa izilwane ezincelisayo zasemanzini.

Okwesibili, lezi zilwane zidinga umoya wokuphila. Inhlanzi ingaphefumula ngama-gill futhi ikhulule i-oksijini ngqo emanzini, kepha imikhomo idinga umoya, ngakho-ke kwesinye isikhathi kufanele ibhukude, kepha ingahlala isikhathi eside ngaphandle komoya kunezilwane zasemhlabeni.

Amahlengethwa yizidalwa ezihlakaniphe kunazo zonke.

Okwesithathu, ukuphuma kwezinhlanzi, namahlengethwa kanye nemikhomo akudingeki ukuba kwenziwe lokhu, bona, njengazo zonke izilwane ezincelisayo, bazala izingane ziphila. Ngaphezu kwalokho, bondla izingane ngobisi lwebele.

Imikhomo nayo iyizilwane ezincelisayo.

Okwesine, umthambo wezilwane ezincelisayo zasolwandle uhlukile kulenhlanzi. Futhi, uhlelo lokujikeleza kwezinhlanzi nemikhomo luhluke ngokuphelele.

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Izilwane zokuqala ezivela ku-cetacean infraorder: pacicetids noma indochius?

Amaphakethe ayengezikhohlisi, kwesinye isikhathi ayehlukaniswa njengemikhomo yokuqala. Bahlala endaweni yePakistan yanamuhla (yingakho igama elithi “whale from Pakistan”) ekuqaleni kwe-Eocene, eminyakeni ecishe ibe yizigidi ezingama-50 edlule. Kwakuyisilwane esasibukeka njengenja, kodwa sinezimpuphu emilenzeni yaso nomsila omude, omncane. Idivayisi yendlebe ihlobene nemikhomo ye-paciceta: inkunzi ye-paciceta yokuhlaziya, efana neyomkhomo, yenziwa kuphela ithambo le-tympanic. Ukuma kwendawo yendlebe ye-pacicet akujwayelekile kakhulu futhi kuthola ama-analogues kuma-cetaceans kuphela. Ekuqaleni, bekucatshangwa ukuthi indlebe yayishintshwa impilo ngaphansi kwamanzi, noma kunjalo, izifundo ezengeziwe zikhombisile ukuthi izindlebe ze-pacicet zilungele kuphela indawo yomoya, futhi uma i-pacicet ngempela idlozi lemikhomo, amandla okuzwa ngaphansi kwamanzi kwakuyinto entsha esetshenziswayo yokuzwa. Ngokuka Tevissen, amazinyo sepakethe nawo afana namazinyo wemikhomo yokumbatha.

UTevissen uphinde futhi wabona ukuthi kwaqalwa isakhiwo esifanayo sezindlebe emfucumfucweni yesilwane esincane esinjengesinyamazane i-Indochius. Indochius waphila cishe izigidi ezingama-48 edlule eKashmir. Lokhu okuncane - usayizi wekati elifuywayo - i-herbivore inezici ezithile ezizisondeza emikhwaneni futhi zikhombisa ukuzivumelanisa nesimo semvelo yasemanzini. Phakathi kwazo, igobolondo lensimbi elisindayo futhi elisindayo lifana negobolondo lamathambo ezinye zezilwane zasemanzini ezinamanzi amancane, njengemvubu, esiza ekunciphiseni ukukhubazeka futhi, ngenxa yalokho, ikuvumela ukuthi uhlale ngaphansi kwamanzi. Lokhu kusikisela ukuthi i-Indochius, njengesigaxa samanzi sanamuhla, sangena ngaphansi kwamanzi ukufihla inyamazane.

Ama-Ambulocetides kanye neRemingtonocetides

Okumangalisa kakhulu kunemikhomo yasendulo yi-ambulocet, eyaziwa nge-Eocene yasePakistan. Ngaphandle, lesi silwane esifuywayo sasifana nengwenya emamitha amathathu. I-Ambulocet kwakuyilwane esisemanzini: imilenze yangemuva kwayo ikulungele kangcono ukubhukuda kunokuhamba ngezinyawo emhlabeni. Cishe wabhukuda, wagoba umzimba ngendiza ebheke phezulu, njengama-otter anamuhla, uphawu kanye nemikhomo. Kucatshangwa ukuthi ama-ambulensi azingelwa njengezingwenya zesimanjemanje, alinde inqola yezinhlanzi nezilwane eza emgodini wokuthambisa.

Izihlobo eziseduze ze-ambulensi kwakungu-remingtonocetides. Abamele lo mndeni bebemincane ngosayizi, bebunobuso obukhulu kunabo futhi bazivumelanisa kangcono nokuphila ngaphansi kwamanzi. Kucatshangwa ukuthi babefana nabathengi besimanje ngendlela yabo yokuphila, bezingela izinhlanzi abaqeshayo.

Kwabamele amaqembu womabili, amathumbu atholakala ekugcineni kwe-muzzle, njengakwezilwane ezincelisayo zomhlaba.

I-Protocetides

I-Protocetides yakha iqembu elikhulu futhi elihlukahlukene, elaziwa ngokutholwa e-Asia, Europe, Africa naseNyakatho Melika. Lo mndeni uhlanganisa inani elikhulu le-genera, eminye yayo ifundwe kahle (ngokwesibonelo, i-Rhodocet, eyaziwa ngokuvela endaweni ephakeme yaseBaluchistan). Onke ama-protocol ayaziwa anezingalo ezikhule kahle nezangemuva ezingaxhasa umzimba emhlabeni, mhlawumbe zaziphila impilo ye-amphibiotic, zihlala emvelweni yasemanzini nasemhlabeni. Akukacaci noma ngabe i-protocetid yayinemali ye-caudal, efana nama-cetaceans anamuhla, kodwa kusobala ukuthi babezivumelanisa kahle nendlela yokuphila yasemanzini. Isibonelo, i-oblium - ingxenye yomgogodla ifakwe kuyo i-pelvis - ku-Rhodocetus yayiqukethe ama-vertebrae amahlanu ahlukene, kanti i-vertebrae eku-oblium yezilwane ezincelisayo zomhlaba ezihlanganiswa. Ema-protoketids, ukuvuleka kwamakhala kushukumise i-snout - lesi yisinyathelo sokuqala kuma-cetaceans wamanje asendaweni yomqhele wamakhala. Le nguqulo emayelana nemvelo ye-amphibian ye-protocetide isekelwa ukutholwa kowesifazane okhulelwe weMayatzet ngesithelo esenziwe ngotshani, ikhanda lakhe liphendukele endaweni yokuthengisa. Lokhu kusikisela ukuthi ukuzalwa kukaMayatset kwenzeka emhlabeni - ngaphandle kwalokho iwundlu lalinethuba lokuminyanisa.

Izici ezinjengokuthi, ngokwesibonelo, ukuba khona kwamaqhubu emikhawulweni yeminwe ye-Rhodocete kukhuluma ngemvelaphi yezinkomo zakuqala ezivela ezingaluswanga.

Ama-Basilosaurids namaDorudontids: ama-cetaceans asolwandle ngokuphelele

Ama-basilosaurus (atholakala ngonyaka we-1840 futhi ekuqaleni enza iphutha lesilwane esihuquzelayo, esichaza igama elithi "reptilian") noDorodon baphila eminyakeni engaba yizigidi ezingama-38 edlule futhi beyizilwane zasolwandle ezihlanzekile. I-basilosaurus yayinkulu njengemikhomo emikhulu yesimanje, kwesinye isikhathi ifinyelela kumamitha ayi-18 ubude. Ama-Dorudontids ayemancane kancane, aze afike kumamitha ayi-5.

Naphezu kwako konke ukufana nemikhomo yesimanje, ama-basilosaurids nama-dorudontids abantula i-frontal-fat protrusion, okubizwa nge-melon, okuvumela ama-cetaceans akhona ukuthi asebenzise ngempumelelo i-echolocation. Ubuchopho be-basilosaurids babuncane, kusuka lapho kungacatshangwa ukuthi baphila impilo bebodwa futhi babengenaso isakhiwo esiyinkimbinkimbi senhlalo njengamanye ama-cetaceans anamuhla. Mayelana nokuguqulwa kwendlela yokuphila yasemanzini emile, ama-basilosaurids akhombisa ukungcola kwezitho zomzimba wasemuva - yize zakhiwe kahle, zincane futhi azisakwazi ukusetshenziselwa ukunyakaza. Kodwa-ke, mhlawumbe babamba iqhaza elisekelayo ekuzeni. Amathambo we-pelvic we-basilosaurid awasaxhunyaniswa emgogodleni, njengoba bekunjalo nge-protocetid.

Ukuvela kwe-echolocation

Imikhomo enamazinyo (i-Odontocetes) yenza i-echolocation, idala uchungechunge lokuchofoza kumaza ahlukene. Imisindvo yomsindo ikhutshwa yi-frontal fat pad (“frontal melon”), ekhonjiswa entweni bese iqoshwa kusetshenziswa umhlathi ophansi. Ucwaningo lwe-squalodon skulls (i-squalodon) lubonisa ukwenzeka kokuqala kwe-ecolocation kulolu hlobo. UC squalodon waphila kusukela ekuqaleni kwe-Middle Oligocene kuya maphakathi neMiocene, cishe eminyakeni eyizigidi ezingama-33- 14 eyedlule, futhi waba nezimpawu eziningi ezifana nemikhomo yanamuhla enamazinyo. Isibonelo, ugebhezi olucwebezelwe ngokuqinile nemicu yomhlathi eyeluliwe iyisici kakhulu se-Odontoceti yesimanje. Ngaphandle kwalokhu, kungenzeka ukuthi umsuka wamahlengezi wesimanje kusuka ku-squalodon uthathwa njengongathandeki.