Sprecher
Beschreibung
The Eastern Himalayan region of Sikkim preserves Gondwana-equivalent sediments exposed within tectonic windows and unconformably overlain by older lithological units. Owing to thrust-related deformation and limited preservation, both mega- and microfossil records are sparse. Early reports of the Glossopteris-Gangamopteris flora were provided by Hooker (1854), Mallet (1874), Acharya et al. (1979), and Singh (1990). However, these studies documented only a few species and lacked detailed morphotaxonomic analyses, leaving the floral diversity and precise age of the succession poorly constrained. Existing palynological data broadly assign the strata to the Damuda-equivalent succession (Late Sakmarian-Early Wordian).
The present study investigates the Gondwana flora exposed along the Nayabazar-Legship road section, Sikkim, to refine its floristic composition, biostratigraphic age, and palaeoecological significance. Megafossils are preserved mainly as impressions and are commonly weathered or deformed, obscuring diagnostic characters. The assemblage is dominated by Glossopteris, Gangamopteris, Paracalamites, Vertebraria, and associated scale leaves, with small and reduced leaf forms being particularly abundant.
Palynological analysis yielded key marker taxa, including Scheuringipollenites barakarensis, S. maximus, Faunipollenites varius, F. singrauliensis, Parasaccites korbaensis, P. obscurus, Striatopodocarpites magnificus, and Indotriradites indicus. These taxa correlate the succession with the Barakar Formation of Peninsular India and indicate an Early Permian (Artinskian) age. The assemblage further suggests deposition under warm and humid climatic conditions. The co-occurrence of Glossopteris-Gangamopteris flora and Scheuringipollenites supports assignment to a Barakar-equivalent horizon of Late Artinskian age. This study enhances understanding of Eastern Himalayan palaeobotany through improved documentation of morphotaxonomic diversity, biostratigraphy, and palaeoecology of extra-peninsular Gondwana floras.