Glossopteris Sentence Examples
The age of the glacial deposits is later than the Glossopteris flora and occurs early in the time of the Gangamopteris flora.
At Bajo de Velis, in San Luis, the plants belong to the " Glossopteris flora," which is so widely spread in South Africa, India and Australia, and the beds are correlated with the Karharbari series of India (Permian or Permo-Carboniferous).
Dvina, Glossopteris, Noeggerathiopsis and other ferns characteristic of the Indian Gondwana beds have been found; and with these are numerous remains of reptiles similar to those which occur in the Indian deposits.
Some of the plants are European forms, others belong to the Glossopteris flora characteristic of India and South Africa.
These include among others, Glossopteris browniana, Gangamopteris cyclopteroides, Sigillaria Brardi, Bothrodendron Leslii, Noeggerathiopsis Hislopi.Advertisement
They are underlain by Jurassic rocks, from beneath which sandstones and shales yielding Glossopteris browniana var.
It is somewhat remarkable that this characteristically southern flora, known as the Glossopteris Flora (from the name of one of the most characteristic genera), has also been found in the north of Russia.
Plants constitute the chief fossils of the Ecca series; among others they include Glossopteris, Gangamopteris, Phyllotheca.
Among plants Glossopteris occurs for the last time.
These contain reptilian remains, and also clear imprints of leaves of the Glossopteris indica, as well as other indications of an ancient vegetation.Advertisement
The Glossopteris flora of India and the southern hemisphere, the age of which has been disputed, but is now regarded as for the most part Permo-Carboniferous, is, however, dealt with in the succeeding section, in connexion with the Mesozoic floras.
The extraordinary abundance of Glossopteris in PermoCarboniferous rocks of Australia, and in strata of the same age in India and South Africa, gave rise to the term " Glossopteris flora for the assemblage of plants obtained from southern hemisphere rocks overlying beds containing Devonian and Lower Carboniferous fossils.
The Glossopteris flora of Australia occurs in certain regions in association with deposits which are now recognized as true boulderbeds, formed during widespread glacial conditions.
Similar glacial deposits occur also in South America, and members of the Glossopteris flora have been discovered in Brazil and elsewhere.
In South Africa, Glossopteris, Gangamopteris and other genera, identical with those from Australia and India, are abundantly represented, and here again, as in India and South America, the plants are found in association with extensive deposits of undoubted glacial origin.Advertisement
On the other hand, the plant-beds of the Permo-Carboniferous age in South Africa, South America, India and Australia demonstrate the existence of a widely distributed vegetation wh i ch agrees in age with the Upper Carboniferous and of the beds in which Glossopteris and other genera make FIG.
The stems, long known from Australia and India as Vertebraria, have in recent years been proved to be the rhizomes of Glossopteris.
It is only recently that undoubted sporangia have been found in close association with Glossopteris leaves.
Associated with Glossopteris occurs another fern, Gangamopteris, usually recognized by the absence of a well marked midrib, though this character does not always afford a satisfactory distinguishing feature.
In view of recent discoveries which have demonstrated the Pteridosperm nature of many supposed ferns of Palaeozoic age, we must admit the possibility that the term fern as applied to Glossopteris and Gangamopteris may be incorrect.Advertisement
There can be little doubt that the Indian Lower Gondwana rocks, in which the boulder-beds and the Glossopteris flora occur, must be regarded as belonging to a vast continental area of which remnants are preserved in Australia, South Africa and South America.
We may next inquire what types occur in the Glossopteris flora agreeing more or less closely with members of the rich PermoCarboniferous vegetation of the north.
In the Tongking area, therefore, a flora existed during the Rhaetic period consisting in part of genera which are abundant in the older Glossopteris beds of the south, and in part of wellknown constituents of European Rhaetic floras.
A similar association was found also in Argentine rocks by Kurtz (Map A, G1), and from South Africa Sigillaria Brardi, Psygmophyllum, Bothrodendron and other northern types are recorded in company with Glossopteris, Glangamopteris and Naeggerathiopsis.
In his account of some plants from the Coal Measures of Kansu (Map A, IV.) Dr Krasser has drawn attention to the apparent identity of certain leaf-fragments with those of Naeggerathiopsis Hislopi, a typical member of the Glossopteris flora; but this plant, so far as the evidence of vegetative leaves may be of value, differs in no essential respects from certain species of a European genus Cordaites.Advertisement
Amalitzky found in beds of Upper Permian age in the province of Vologda (Russia) (Map A, V.) species of Glossopteris and Naeggerathiopsis typical members of the Glossopteris flora, associated with species of the ferns Taeniopteris, Callipteris and Sphenopteris, a striking instance of a commingling in the far north of the northern hemisphere Permian species with migrants from " Gondwana Land."
Evidence of the same northern extension is supplied by floras described by Schmalhausen from Permian rocks in the Pechora valley (Map A, VI.), the Siberian genus Rhiptozamites being very similar to, and probably generically identical with, Naeggerathiopsis of the Glossopteris flora.
A few plants described by Potonie from German and Portuguese East Africa demonstrate the occurrence of Glossopteris and a few other genera, referred to a Permo-Triassic horizon, in a region slightly to the north of Tete in the Zambesi district (Map A, I.), where typical European plants agreeing with Upper Carboniferous types were discovered several years ago, and described by Zeiller in 1882 and 1901.
Having seen how the Glossopteris flora of the south gradually spread to the north in the Permian period, we may now take a brief survey of the succession of floras in the northern hemisphere, which have left traces in Mesozoic rocks of North America, Europe and Asia.
Of other Equisetales there are Schizoneura and Phyllotheca; the former first appears in Lower Gondwana rocks as a member of the Glossopteris flora, migrating at a later epoch into Europe, where it is represented by a Triassic species.
Starting with the Permo-Carboniferous vegetation, and omitting for the moment the Glossopteris flora, we find a comparatively homogeneous flora of wide geographical range, consisting to a large extent of arborescent lycopods, calamites, and other vascular cryptogams, plants which occupied a place comparable with that of Gymnosperms and Angiosperms in our modern forests; with these were other types of the greatest phylogenetic importance, which serve as finger-posts pointing to lines of evolution of which we have but the faintest signs among existing plants.
In the southern hemisphere the Glossopteris flora succeeded a Lower Carboniferous vegetation with a rapidity similar to that which marked the passage in the north from Palaeozoic to Mesozoic floras.
It was from this Glossopteris flora that several types gradually migrated across the equator, where they formed part of the vegetation of more northern regions.
The difference between the Glossopteris flora and those which have left traces in the Upper Gondwana rocks of India, in the Wianamatta and Hawkesbury beds of Australia, and in the Stormberg series of South Africa is much less marked than that between the PermoCarboniferous flora of the northern hemisphere and the succeeding Mesozoic vegetation.
It was replaced by the Glossopteris flora which is assumed to have originated in a vast continental area (Gondwana land), of which remnants remain in South America, South Africa and Australia.
The Glossopteris flora gradually spread to the northern hemisphere and intermingled with the later Palaeozoic flora which still persisted.
The most important evidence on which this conclusion is based is afforded by the occurrence of European forms of Carboniferous shells in marine strata in New South Wales, which are intercalated between Coal Measures containing members of the Glossopteris flora, and.