Adoketophyton
| Adoketophyton | |
|---|---|
 | |
| Scientific classification | |
| Kingdom | Plantae |
genus (en)  | Adoketophyton ,
|
Adoketophyton Ya kasan ce wani HALITTAR na dadaddun jijiyoyin bugun gini shuke-shuke da Early Devonian (Pragian mataki, a kusa da 410 shekaru miliyan da suka wuce ). An fara bayyana shuka a cikin 1977 dangane da samfuran burbushin halittu daga Tsarin Posongchong, gundumar Wenshan, Yunnan, China. Waɗannan asali an sanya musu suna Zosterophyllum subverticillatum ; daga baya an canza nau'in zuwa wani sabon jinsi kamar Adoketophyton subverticillatum.[1] Analysisaya daga cikin binciken cladistic ya ba da shawarar cewa lycophyte ne, wanda ke da alaƙa da zosterophylls . Sauran masu binciken suna ɗaukar matsayinta a cikin tsirrai na jijiyoyin jini a matsayin mara tabbas.[1]
Bayani[gyara sashe | gyara masomin]
Kamar sauran tsirrai na farko na Devonian, sporophyte na Adoketophyton ya ƙunshi tushe mai tushe (gatura), kamar 1 zuwa 2.5 mm a diamita. Waɗannan sun yi daidai daidai ko daidai (pseudomonopodially). Kwayoyin jijiyoyin sa sun kasance masu sauƙi, sun ƙunshi silinda na tsakiya (centrarch ) na xylem na farko tare da tracheids na G. Burbushin halittu yana ba da shawarar cewa tushe wanda baya ɗaukar sporangia da farko ya tattara nasihu (circinnate), daidai da sauran " zosterophylls ", kuma yayi kama da hanyar da ferns na zamani ke girma. Wani fasali na musamman na wannan nau'in a tsakanin tsirrai masu irin wannan shekaru shine yadda aka haifi sporangia (gabobin da ke haifar da spore). Mai tushe mai taushi yana da madaidaicin '' strobili '', tsarukan da ke kama da kunun alkama, wanda ya ƙunshi layuka huɗu na tsaye na gabobin ganye mai kama da fan (sporophylls), kowannensu yana da ɓoyayyen ɓarna a gefen da ke fuskantar tushe (adaxial). Fushin da aka daidaita ya kusan zagaye kuma ya rarrabu (cirewa) tare da nisa mai kauri zuwa kashi biyu daidai. Mai yiwuwa sporophylls sun sami nama na jijiyoyin jini.[1]
An bayyana jinsin na biyu, A. parvulum, a cikin 2011. Nau'in ya bambanta a girman gabaɗaya; Misali, mafi girman strobili da aka samu shine 90 mm a cikin A. subverticillatum, amma 17 kawai mm tsawon a A. parvulum . Girman dangi na sporophylls da sporangia suma sun bambanta: sun kasance kusan tsayi iri ɗaya a cikin A. parvulum, yayin da sporangia ta kasance rabi zuwa uku na tsayin sporophylls a cikin A. subverticillatum .
Phylogeny[gyara sashe | gyara masomin]
An kadda da cladogram acikin 2004 . Sauran masu binciken sun kammala cewa cakuda ɗan tsoka 'tsoka' na jijiyoyin jijiyoyin jini da 'ci gaba' sporophylls yana ba da shawarar cewa halittar ta samo asali ne daga lycopsids, don haka ba a tabbatar da sanya matsin lamba.[1]
Hanyoyin waje[gyara sashe | gyara masomin]
- Cladogram Archived 2012-12-04 at Archive.today daga Crane, Herendeen & Friis 2004
Manazarta[gyara sashe | gyara masomin]
- ↑ 1.0 1.1 1.2 1.3 Hao, Shougang; Wang, Deming & Beck, Charles B. (2003), "Observations on anatomy of Adoketophyton subverticillatum from the Posongchong Formation (Pragian, Lower Devonian) of Yunnan, China", Review of Palaeobotany and Palynology, 127 (3–4): 175–186, doi:10.1016/S0034-6667(03)00119-2