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BIRBAL SAHNI INSTITUTE OF PALAEOBOTANY Annual Report 2004-2005 Component 4: Palaeofloral and dispersed organic matter characterization in Early Cretaceous deposits of central India The Early Cretaceous deposits exposed at clay mine cut section near Chhoti Pali village and environs (Umaria district) embody Ginkgoalean leaves and ovules attributed to Ginkgo and Ginkgoites, resembles with extant genus Ginkgo biloba. The extant Ginkgo biloba shows several ancestral fossil records. The Early Cretaceous deposits of Jabalpur Formation embody bilobed compressed leaves; while other recorded forms from older deposits show transitional features in evolutionary lineage. These fossil forms retained primitive as well as advanced vegetative features that coexisted during long geological time span. An evolutionary trend is also visible in Ginkgoalean seeds as the mature ovules grow in size and numbers are reduced due to reduction in number of ovules and pedicles. They tend to become contiguous by virtue of shortening and eventual loss of pedicles. Therefore, it is inferred that the Early Cretaceous leaves of Ginkgo from Jabalpur Formation are evolutionary advanced than the deeply dissected leaves of Ginkgoites rajmahalensis of other basins. Studied another Early Cretaceous deposits (carbonaceous shale) exposed at nala cut section on the way from Chandia to Umrar River. This shale embody well preserved plant fossils belonging to Ptilophyllum flora, spore-pollen and organic matters, while upper sandstone layer contain disarticulated pieces of skeletons (?tetrapods). Well-diversified and well-preserved plant fossils are collected from blackish-gray shale exposed in mine cut section at Belkher (Amravati District, MS). They are represented by Matonidium indicum, Cladophlebis indica, Ptilophyllum cutchense, and P. acutifolium. Taeniopteris spatulata, Brachyphyllum sehoraensis, Elatocladus plana and Araucarites cutchensis. The flora shows dominance of pteridophytes and conifers. Comparative analysis suggests that Leaf with petiole of fossil Ginkgo biloba from Jabalpur Formation the flora is coeval to Dhragdhara, Gadeshwar and Himmatnagar floral assemblages of western India. Macerated about 50 samples collected from Jhala, Tekan and Machrar River section for palynofacies study. Slides of productive samples have been made and scanned. Madhav Kumar & Neeru Prakash Component 5: Morphotaxonomy, floristics, biostratigraphy and palaeoecological studies in Korba and Hasdo-Arand coalfields Processed, photographed (56 specimens) identified, and studied megafossil specimens (around 230) collected from southern part of Korba Coalfield (Chhattisgarh State). Seven species of Glossopteris viz., G. communis, G. indica, G. browniana, G. maculata, G. taeniodes, G. euryneura and G. feistmantelli along with the taxa Gangamopteris obliqua, Noeggerathiopsis hislopii, Lidgettonia mucronata and Venustostrobus sp. have been identified. The overall assemblage suggests an Upper Barakar age to this flora. K.J. Singh 7
BIRBAL SAHNI INSTITUTE OF PALAEOBOTANY Annual Report 2004-2005 Birbal Sahni Institute of Palaeobotany Project 3: Vegetational patterns, Palaeogeography and Palaeoenvironmental analysis of Satpura-Wardha-Godavari and Gujarat- Rajasthan basins Component 1: Palaeobotany, evolution, biostratigraphy and palaeoecology of Gondwana sediments of Wardha-Godavari Basin Systematically described and finalised study on megafossils from Kamthi Formation of Bazargaon- Satnaori and Semda areas of Kamptee Coalfield, Wardha Basin. The assemblage comprises equisetales, viz. Trigygia speciosa, Schizoneura gondwanensis, equisetalean axes, filicales– 2 species of the genus Neomariopteris (N. hughesii, N. polymorpha), glossopteridales– 21 species of the genus Glossopteris, two scale leaves, a seed taxon– Maheshwariella sp., and cordaitales– Noeggerathiopsis sp. The assemblage is similar to that of Raniganj Formation of Damodar Basin and indicates an Upper Permian age. Macerated samples from Barakar Formation of Majri, Hindustan Lalpeth, Durgapur, Padampur and Ballarpur collieries (Wardha Valley) for recovery of palynomorphs. The samples have yielded a rich assemblage of palynofossils. Quantitative and qualitative study is in progress (with Neerja Jha). Also studied palynomorphs from Permian Gondwana Sequence of Umrer Coalfield, Nagpur district. The microspores assemblage (22 genera and 40 species) is characterized by dominance of radial monosaccates (chiefly Parasaccites) and subdominance of non-striate disaccates (chiefly Scheuringipollenites). Presence of Crucisaccites and Caheniasaccites is also recorded. Karharbari palynozone has been demarcated in lithologically designated Barakar Formation. A paper has been finalized on the aspect (with Neerja Jha & A. Rajanikanth). Rajni Tewari Component 2: Palynology of Gondwana sediments of central and southern parts of Godavari Basin and its phytogeographic significance Early Triassic palynoassemblage recorded at 140.50 m in bore-hole SSP-133 shows high percentage of taeniatecingulated cavate miospores, viz. Lunatisporites, Lundbladispora and Densoisporites along with presence of stratigraphically significant taxa Chordasporites, Klausipollenites, Lunatisporites and Playfordiaspora. Striate disaccates decline at this level. Occurrence of megaspores is also noticed. Identified a variety of azonate and gulate megaspores from Barakar and Raniganj formations of Kachinapalli and Gundala areas of Godavari Valley coalfields. Detailed study is in progress (with Rajni Tewari). Late Permian (Raniganj) palynoflora has been recorded in equisetalean axes bearing sediments in bore-hole MSP-21 (at 142.5-143.0 m). Neerja Jha Component 3: Biostratigraphy and palaeoenvironmental studies in Wardha and northern part of Godavari Valley Coalfield Work could not be reported due to sudden demise (in June 2004) of A.P. Bhattacharyya. Component 4: Morphological and evolutionary significance of Satpura Gondwana flora and their bearing in stratigraphy, palaeoecology and palaeoenvironment Carried out the morphotaxonomical analysis, description, identification and comparison of different types of seeds belonging to different species of Cordaicarpus, Samaropsis, Alatocarpus, Cornucarpus, and two new types showing long stalk and large size (>2 cm in diameter). The affinity and affiliation of Arberiella-type of sporangium has also been discussed. The possible presence of calamitalean axis possessing alternating grooves at the nodal region and Cordainthus- type of seeds indicate the presence of extragondwanic elements in Satpura Gondwana Basin. The finding further supports the presence of mixed flora in the typical flora of Gondwana represented by Botrychiopsis, Buriadia, Rubidgea along with the glossopterid forms. The different types of flora at successive horizons have been discussed to examine the palaeophytodiversity trends in Indian scenario. It has been observed that there is direct and indirect bearing of palaeobotanical investigations in the conservation of present day biodiversity. Further study is under progress. A field work was also undertaken to different areas of Pench-Kanhan Valley and Pathakhera Coalfield for fresh collection of plant fossils. A.K. Srivastava 8
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