Tuesday, 25 May 2021

Biochemical and ultra structural studies also suggest

Biochemical and ultra structural studies also suggest



  It is a period of Palaeozoic era. This period started years back. It lasted 35 million years. This period was from 460 million years ago and ended by 425 million (ii) Ordovician period (i) Cambrian period (iii) Silurian period (M) Mississipan period (vi) Pennsylvanian period (iv) Devonian period (vii) Permian period Cambrian Period : (i) It is a period of Palaeozoic era. This period is named tter the Roman city Wales meaning Cambrian. The rocks of this period was first discovered in that city.

 This period was between 600 million years and 525 million years ago. The climate was very cool. The fossils of cryophycean algae were recorded. Ordovician Period : (ii) It is a period of palaeozoic era. This period is named after the ancient tribe Ordovices inhabited in Wales city. This period lasted for 65 million years. The fossils of Chara and Red algae were reported from sediments of this period. 

(iii) Silurian Period : It is a period of Palaeozoic era. This period is also named after the ancient tribe of Wales city. It last for 35 million years. The fossils of diatoms, brown-algae, club mosses (Lycopsida of Pteridophytes) and herbaceous marshes were discovered from rock deposits of this period. 

(iv) Devonian Period :Only Chiorophyceae (monophyletic origin) or Chtorophyceae and Phrdeophyceae (polyphyletic origin) have been considered as the progenitor of this group by these workers. Biochemical and ultra structural studies also suggest a strong affinity between algae and archegoniate plants (Stebbins and Hill, 1980: Whatley, 1982; Graham, 1982).


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