Glossopteris (fossil kind)

Glossopteris is a kind of plants of the extinct order of the Glossopteridales . It is the kind the best known one of this kind. This last (sometimes called Arberiales or Dictyopteridales ) belongs to the group (undoubtedly a division) extinct of the Pteridospermatophytes .

The Glossopteridales are abundant with the Permien. They are regarded as a stratigraphic marker of Permian although specimens of age Trias were reported and that there exists an abnormal occurrence with the Jurassic .

Distribution: India, Australia, South America, the Antarctic, Africa

Etymology

“ Glossopteris ” comes from the Greek glossa , who means “language”, because of the form of the sheets.

History

It is the distribution of the fossils of Glossopteris which led the geologist Eduard Suess to consider that there had been in the past a connection between India, Australia, Africa, South America and the Antarctic. It called this “super-continent” Gondwana according to an area of India (Gondwâna) where Glossopteris is abundant. This distribution of Glossopteris will come to support the theory of Alfred Wegener on the Continental drift.

Description

Port: Glossopteris was a woody plant which had a wearing of bush or tree. The largest specimens could have reached 30m top.

Trunk and branches: the trunks and the branches of Glossopteris have a dense wood, with marked rings of growth. The rays are uniserial, the radial walls of the trachéides carry punctuations araucarioïdes. The wood of Glossopteris is sometimes placed in the kind of form Araucarioxylon .

Sheets: the sheets of Glossopteris are simple, with a lancéolée form. They can measure until 30cm length. They have a central vein, the nervation is réticulée. the sheets are laid out on the branches out of tight propellers. It seems that as at the current Ginkgo biloba , Glossopteris had short growths and long growths. The number of species of sheets described is important, probably because of the absence of a standardized classification. For example 70 species were described only in India.

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