Xa sithetha ngemvelaphi yezityalo, igama lisoloko livela: Cooksonia. Sisityalo esivele phakathi kwixesha leSilurian, oko kukuthi, phakathi kweminyaka engama-428 kunye nama-423 yezigidi zeminyaka eyadlulayo.
Izityalo ezininzi esizaziyo namhlanje zinokuphuhliswa, ukusuka kwimithi emikhulu ukuya kwientyatyambo. Kodwa, Ibinjani?
Iimpawu zeCooksonia
Umlinganiswa wethu ophambili yayisisityalo esihlala phantse kuyo yonke imimandla yehlabathi: i-Ireland, iWales, iNgilani, i-Bolivia, i-United States, i-Great Britain, i-Australia. Wayengekho ngaphezulu kweesentimitha ezili-10 ubude, Kodwa ke kuyathakazelisa ukuyazi kuba yayisesinye sezityalo zokuqala zomhlaba ezihlala eMhlabeni.
Yayingenamagqabi, kodwa iziqu zayo, ezazime okwe Y, zazinako ukuvelisa iklorofili kwaye, ke ngoko, ifotosinthesisi kunye nokukhula. Kwakungenangcambu njengoko sizazi namhlanje, kodwa yayifakwe emhlabeni ngokusebenzisa iriziziz ethe tyaba. Indlela yayo yokuphindaphindeka yayihamba ngokudlula kwembewu eyenziwe kumqukumbelo wesiqu ngasinye, sporangia, nangona kungacaci ukuba kwenzeke njani.
Iintlobo
Ukuza kuthi ga ngoku, iintlobo ezisixhenxe ezahlukeneyo sele zifunyenwe:
- C.pertoni, ngo-1937
- C. hemisphaerica, ngo-1937
- C. icambrensis, ngo-1979
- C. iparanensis, ngo-2001
- ibhomu c., ngo-1980
- C. banksii, ngo-2002
Nangona ingathathwa njengesikhokelo sefosili, kunjalo yayiyidigri yokuvela kwindalo yokuqala. Ngapha koko, kwafunyanwa iintlobo ezine ezahlukeneyo zesifo esivela kwiintlobo ezahlukeneyo zesporangia kolunye lweentlobo zikaCooksonia.
Ezi zityalo zachazwa ngu Bhritane u-William Henry Lang ngo-1937, owazithiya igama ngo-Isabel Cookson, owasetyhini owaqokelela iintlobo zezinye iintlobo zeminyaka emithathu eyadlulayo ePerton Quarry.
Ucinga ntoni ngesi sityalo singasekhoyo?