Acta Palaeobotanica 46(2): 101–118, 2006 Permian biodiversity of Mahanadi Master Basin, Orissa, India and their environmental countenance SHREERUP GOSWAMI 1 , MADHUMITA DAS 2 and B.C. GURU 3 1 P.G. Department of Environmental Sciences, F. M. University, Vyasa Vihar, Balasore-756019 (Orissa), India 2 P.G. Department of Geology, Utkal University, Vani Vihar, Bhubaneswar-751004 (Orissa), India 3 P.G. Department of Zoology, Utkal University, Vani Vihar, Bhubaneswar-751004 (Orissa), India; e-mail: goswamishreerup@yahoo.com Received 25 November 2005; accepted for publication 24 November 2006 ABSTRACT. The Permian geology and megafloral, miofloral, acritarchs and ichnofossil assemblages of different basins of the Mahanadi Master Basin, Orissa are enumerated in the present study. This review paper mainly deals with the plant species diversification of Glossopteris assemblage in five different lithological formations (Talchir, Karharbari, Barakar, Barren Measures and Lower Kamthi / Raniganj) and the development of flora during Permian in the Mahanadi Master Basin, Orissa. Among the mega-floras, leaves are the dominant part of the preserved flora followed by fertile forms, root forms and seed etc. The Glossopteris flora has been meticu- lously studied to portray the palaeoenvironment (mainly palaeoclimate and palaeovegetation) and palaeoflo- ristics of these basins. Records of typical marine acritarchs and ichno fossils in this master basin in different Permian formations depict there could have been marine influence. These evidences of signature for marine environment demonstrate a paralic (coastal marine to deltaic) mode of origin of the Gondwana coal beds and associated sediments. KEY WORDS: Glossopteris flora, Permian, Talchir, Karharbari, Barakar, Lower Kamthi, India INTRODUCTION The Permian Gondwana sediments of Mahanadi Master Basin occupy an area of about 3 500 sq. km and are mainly exposed in five sedimentary basins, viz. Talcher, Ib River, Katringia, Gaisilat and Athmalik basins. The biodiversity of the Mahanadi Master Basin during Permian has been assessed and the palaeoenvironment (mainly palaeoclimate and palaeovegetation) of different basins of this master basin has also been analysed. More- over, records of typical acritarchs and ichno fossils of marine signature are discussed to get inferences on mode of origin of the Gondwana coal beds and associated sediments. Apparent diversity of plant (especially of gymnosperm, pteridophyte, and some major Permian genera) and ichno taxa are analysed. The overall biodiversity of this master basin is also interpreted. GEOLOGY AND STRATIGRAPHY The Mahanadi Master Basin, Orissa, con- sists of five sedimentary basins: Talcher, Ib River, Katringia, Gaisilat, and Athmalik. The stratigraphy of the Permian of Mahanadi Mas- ter Basin is presented on Table 1. The Ib River Gondwana basin is named after a tributary of the Mahanadi. The basin is located in the south-eastern part of Mahanadi Master Basin (Fig. 1) and occupies an area of 1460 sq. km. The basin is bounded by latitudes 21°30′ and 22°14′N and longitudes 83°32′ and