1991-92 - Birbal Sahni Institute of Palaeobotany

1991-92Maheshworiopteris digit010 gen. et sp. novo fromEarly Pennian of RajmahaJ Hills.digitata fronds reported from Australia. In the absence of knowledge about fertilestructures, its exact affinities remain uncertain. The taxon is named asMaheshwariopteris digitata gen. et sp. novoProgramme 2.6ObjectiveUshaBajpai:Pattern of evolving palynofloras throughGondwana Sequence in Damodar Graben: To search for characters in dispersed spores andpollen useful for determining major changes inpatterns of morphologiesBased on evolutionary changes in the morphology of the pollen groups, theirFADs and LADs, eleven Biohorizons and ten Interval- Zones have been identifiedthrough the span of Gondwana Sequence. For this purpose simple character-stateanalysis was done. By extrapolation of lineages, four unique monosaccate and onesimple disaccate organizations could be identified to have their origin in the EarlyCarboniferous stock of Australia. The relation cladistics has reinforced the validityof the proposed biohorizons. The cladograms and stratograms together depict themaximum radiation at the lower Upper Talchir and at prr boundary.Vijaya & R.S. TiwariAnalysis of data on Permo-Triassic boundary has revealed that there had beenno mass extinction at this boundary. It was an episode of high turnover. Theclimatic changes and alteration in geomorphology due to new tectonic-setup at theboundary were responsible for a major shift in evolution of palynomorphs. Eightpalynoevents have been identified along the latest Permian-earliest Triassic transitionand they have been tagged with comparable palynoevents in various basins17