Ukufunda emadwaleni
Akheka Kanjani Amafosili Amadayinaso?
Impendulo emfushane
Ifosili ledayinaso lakheka lapho izinsalela noma imikhondo ihlala isikhathi esanele ukuze ibe yingxenye yomlando ogcinwe emadwaleni. Ethanjeni, ukugqibeka namanzi angaphansi komhlaba acebile ngamaminerali kuvame ukusiza ukuligcina. Emkhondweni wonyawo, okubalulekile ukugcina umnyatheliso ungaphazamisekile. Ayikho kulezi zinqubo egcina umlando ophelele wokuphila kwesilwane.
Ukugqibeka kunikeza ithambo ithuba lokusinda
Izidumbu eziningi ziyanyamalala. Izilwane ezidla izidumbu ziyazihlakaza, amagciwane nezinye izinto eziphilayo ezincane ziyazidla, kanti isimo sezulu siqhekeza okusasele. Inhlabathi enqwabelanayo ingamisa lokhu kubhujiswa ngokumboza isidumbu noma amathambo ahlakazekile. Izicubu eziqinile ngokuvamile zisinda kangcono kunemisipha noma izitho zangaphakathi. I-National Park Service ichaza ukuthi kungani ukunqwabelana okuqhubekayo kwenhlabathi kwenza amathafa ezikhukhula nezindawo ezifana nawo zibaluleke kangaka emlandweni wamafosili.
Lokhu kudala ukungalingani kulokho okugciniwayo ngaphambi kokuba isazi samafosili sithathe isando. Isilwane esihlala eduze komfula onodaka sinamathuba ahlukile okulondolozeka kunesihlala endaweni ephakeme egugulekayo. Ngakho igebe emlandweni wamafosili alisho ngokuzenzakalela ukuthi kwakungekho ukuphila ngaleso sikhathi.
Ithambo liphenduka kanjani ifosili?
Ithambo linezikhala ezincane. Amanzi angaphansi komhlaba angaletha amaminerali ancibilikile kulezo zikhala, lapho kukhula khona amakristalu. Lokhu kubizwa ngokuthi i-permineralization, ukugcwaliswa ngezinto zamaminerali. Ukushintshwa kwento yokuqala kuhlukile: yona iyancibilika bese amaminerali ethatha indawo yayo. Zombili izinqubo zingathinta ifosili elifanayo. Imininingwane emincane yokwakheka komzimba ingagcineka noma ukwakheka kwamakhemikhali sekushintshile.
Incazelo ye-Natural History Museum ilandela ukugqibeka, ukunqwabelana kwezinsalela nokufakwa kwamaminerali. Lezi zinqubo zingaqhubeka ngesikhathi esifanayo; alikho iwashi elilodwa elenza wonke amathambo agqitshiwe abe amafosili ngemva kwenani elinqunyiwe leminyaka.
| Inqubo | Okwenzekayo | Okungagcinwa yifosili |
|---|---|---|
| Ukugcwaliswa ngamaminerali | Amaminerali agcwalisa izimbotshana | Ukwakheka kwangaphakathi kwethambo |
| Ukushintshwa | Amaminerali athatha indawo yento yokuqala | Okunye kokuma nemininingwane yokuqala |
| Umnyatheliso wemvelo nesifaniso esigcwalisa wona | Kusala umnyatheliso ongagcwaliswa kamuva | Ukuma kwangaphandle noma kwangaphakathi |
| Umnyatheliso | Ingaphezulu lishiya uphawu enhlabathini enqwabelene | Ukuthungwa kwesikhumba, umumo wophaphe noma umkhondo wonyawo |
Ifosili akudingeki libe nethambo
Idayinaso elihamba endaweni emanzi lingashiya imikhondo egcina imboziwe futhi ilondolozekile. Ubulongwe obuphenduke ifosili, obubizwa nge-coprolite, bugcina ubufakazi bomunye umsebenzi. Lawa amafosili emikhondo. Izinyo noma ithambo elilodwa lomgogodla liyifosili lomzimba. Umehluko uthi ubufakazi bumelela umzimba wento ephilayo noma into eyayenza; awuhlukanisi amafosili “angempela” nalawo “angempela kancane”.
Izindawo zokunqwabelana ezingavamile ngezinye izikhathi zigcina imininingwane engekho ezinhlakeni zamathambo ezivamile. Umhlahlandlela wethu wezimpaphe zamadayinaso ubonisa ukuthi kungani lokho okutholakala ngokungavamile kungashintsha umfanekiso owakhiwe kabusha.
Kungani amafosili egcina evela phezu komhlaba?
Idwala elakhiwe ngezinsalela lingahlala ligqitshiwe, ligobeke noma liphakame, bese ligcina livezwa ukuguguleka. Lokhu kwenza ifosili litholakale kodwa futhi kuqala enye inkathi yokulimala. I-American Museum of Natural History ichaza ukuthi abacwaningi basebenzisa kanjani amamephu ezakhiwo zomhlaba namadwala avele obala ukuze bakhethe lapho bezofuna khona.
Okubalulekile akulona nje ithambo elizimele. Ungqimba lwedwala, indawo elikuyo nobudlelwano balo nezinye izinsalela kunikeza umongo. Ukuze ubeke okutholakele emlandweni wamadayinaso, qala nge-Triassic, i-Jurassic ne-Cretaceous, bese ubuza ukuthi ibuphi ubufakazi obunquma ubudala bongqimba oluthile.
Imibuzo nezimpendulo
Ingabe amathambo amadayinaso angamafosili angamathambo angempela?
Ayizinsalela zangempela zezilwane ezake zaphila, ezashintsha ngesikhathi ziba amafosili. Ifosili lemvelo lihlukile esifanisweni esenziwa namuhla emnyuziyamu kusetshenziswa isampula.
Ingabe wonke amadayinaso agqitshiwe aba amafosili?
Cha. Izinsalela zingabola, zincibilike, ziphazamiseke noma zibhujiswe izinqubo zomhlaba zakamuva. Ukugqibeka kwandisa ithuba lokulondolozeka kodwa akukuqinisekisi.
