Ukutholwa kwe-paleontological e-Morocco kunikeze imikhondo eqondile yokuthi kanjani i-symmetry ye-starfish, inhlangano enezinhlaka ezinhlanu ezihlukanisayo ezilwaneni. Ucezu oluyisihluthulelo yi-echinoderm ye-Cambrian ebhala, ngemininingwane engavamile, ukuguquka kusuka ku-a umzimba wamazwe amabili maqondana ne-pentaradial architecture.
Umlingiswa oyinhloko wocwaningo ngu I-Atlascystis acantha, imfucumfucu yeminyaka engaba yizigidi ezingu-510 yatholakala ku-Atlas Anti-Atlas yase-Moroccan futhi yahlaziywa yiqembu lamazwe ngamazwe eliholwa ngokubambisana I-IGME-CSICUcwaningo, olushicilelwe kumagazini i-Current Biology, lubonisa ukuthi lesi sidalwa sihlanganisa izici ezimbili kanye nabalingiswa ababelindele i-symmetry yama-radius amahlanu ye-echinoderms yesimanje.
Ukutholwa ohlela kabusha umsuka we-stellar symmetry
Kuma-echinoderms anamuhla, njenge-starfish, i-pentaradial symmetry Ibusa esiteji sabantu abadala, nakuba izibungu zayo zihlangene. I-Atlascystis acantha iphula lolu hlelo ngenxa yokuthi igcine ukuhlangana kwezinhlangothi ezimbili ekuvuthweni, kuyilapho ikhombisa izakhiwo ezikhomba uguquko oluya kuhlelo lomzimba we-radial, okwenza kube isixhumanisi sokuziphendukela kwemvelo kubalulekile.
Ukuze uqonde umehluko, kufanelekile ukukhumbula ukuthi i- i-pentameric symmetry ihlukanisa umzimba ube imikhakha emihlanu elinganayo, okuthile okubonakala ku-starfish. Le nhlangano ayikhethekile kubo: iphinde ibonise ama-urchin olwandle, ama-crinoid nama-holothurians, wonke amalungu eqembu echinoderms, Ngokungafani ne- ama-cnidarians ane-radial symmetry.
Yini evezwa yi-Atlascystis acantha nokuthi kungani ibalulekile
Ucwaningo luyakhomba I-Atlascystis acantha njenge-echinoderm endala eyaziwa nge i-symmetry yamazwe amabili esigabeni sabantu abadala futhi ibhalwe ezigabeni ezahlukene zokuthuthuka. I-anatomy yayo ihlanganisa izici zokuqala nezinto eziwuphawu lwamafomu e-radial, ikubeka endaweni ebalulekile emaphakathi yokwakha kabusha ukuguquka kwe-morphological.
Phakathi kwalezi zici, okulandelayo kuyagqama: ambulacra, imigudu ehlotshaniswa nesistimu ye-vascular yamanzi lapho i-echinoderms yamanje ihamba khona, idla futhi inamathisele ku-substrate. Ukuba khona kwe-ambulacra efomini elinjalo lasendulo lamazwe amabili kusiza ukuxhumanisa ngokuqondile ama-echinoderms okuqala nawo inzalo yesimanje.
Kusukela endizeni yamazwe amabili kuya emisebeni emihlanu: indima ye-ambulensi
Ukhiye wokuziphendukela kwemvelo usekutheni izinto eziphilayo zahlelwa kabusha futhi zaphindaphindeka kanjani. ambulacra ngokuhamba kwesikhathi. Ubufakazi bukhombisa indlela lapho ukuphindwaphindwa kanye nokuhlelwa kabusha okwalandela kwalezi zakhiwo kugcine sekusungule isici sokulinganisa okukhulunywayo okuyisihlanu kwe izinkanyezi zasolwandle.
- Amafomu amadala kakhulu ayakhombisa ambulacra ezimbili, iphethini elula, yamazwe amabili.
- Ezigabeni ezithile zozalo a ukuncishiswa kokukodwa, okulandelwa ukuphindaphinda okwengeziwe.
- Uchungechunge lokuphindaphinda kwaholela kuqala ku tres futhi ekugcineni ku izikhulumi ezinhlanu, ukusungula i-pentaradial architecture.
Lolu hambo luchaza ukuthi kungani ama-echinoderm amanje, naphezu kokubonakala kwawo kokulinganisa kwe-radial, egcina imprint yamazwe amabili ekuthuthukisweni kwawo nokuthi pentadiality kuvele njengesixazululo esizinzile eqenjini.
I-fossil yafundwa kuphi futhi kanjani
Izibonelo zivela kumadiphozithi we I-Lower Cambrian e-Anti-Atlas (Morocco), isifunda esikhethekile sokuphenya ukuhlukahluka kwangaphambi kwesikhathi kwezilwane. Lo mongo we-geological uhlinzeka ngohlaka lwesikhathi lokuzungeza 510 izigidi zeminyaka, ukhiye wokuqonda ukuvela kwezinhlelo ezintsha zomzimba.
Ithimba lafaka isicelo Imisebe ye-synchrotron ukuthola ukwakhiwa kabusha kwezinhlangothi ezintathu ezinesinqumo esiphezulu ngaphandle kwesidingo sokulungiswa komshini, ngaleyo ndlela kugwenywe ukuguqulwa kwezinto. Ngenxa yale nqubo, kube nokwenzeka ukubheka ngokunembile imininingwane yangaphakathi nengaphandle eveza ukuthi izakhiwo zezinto zazihlelwe kanjani. umzimba we-fossilized.
Imithelela yokuqonda i-starfish yanamuhla
Ngokubhala isiteji esiphakathi phakathi kobudlelwane bokhokho kanye i-pentaradial symmetry, umsebenzi ugcwalisa igebe kurekhodi lezinsalela futhi unikeza isisekelo se-anatomical sokuhumusha ukuthi kungani i-starfish inezingalo ezinhlanu. Isixhumanisi esinikezwe yi- ambulacra ixhumanisa ukuhlukahluka kokuqala kwama-echinoderm nempumelelo yawo yakamuva emangalisayo.
Inhlanganisela yensalela eyisihluthulelo, umongo onembile we-geological kanye nezindlela ezithuthukisiwe zokucabanga kuvumela ukwakha kabusha ushintsho indiza yomzimba yamazwe amabili kwenye i-radial, iveza ukukhanya okusha kokuthi i-symmetry ewuphawu lwe izinkanyezi zasolwandle nezihlobo zabo eziseduze.
