Mesozoic phytoclast records in the Sriperumbudur (Palar Basin), Kota (Chintalapudi Sub-Basin) and Dubrajpur (Rajmahal Basin) formations, India

Abstract

The studies of fossil plant cuticles in palynological samples recovered from three cored boreholes located in the Indian states of Andhra Pradesh (Kota/Gangapur Formation, Chintalapudi Sub-basin, Godavari Graben, Jurassic-Cretaceous), Tamil Nadu (Sriperumbudur Formation, Palar Basin, Upper Jurassic-lowermost Cretaceous), and Jharkhand (Dubrajpur Formation, Rajmahal Basin, Upper Jurassic-Lower Cretaceous) are presented herein. Cuticles and palynomorphs were recovered by standard palynological practices in the Gondwana Palynological Laboratory of the Birbal Sahni Institute of Palaeosciences, Lucknow, India. Fossil specimens were examined under a binocular microscope and photomicrographs were taken with a digital camera. Twenty seven morphotypes of fossil cuticles (occasionally representing stomata, trichomes and secretory structures) and other tissues (e.g., a plicate parenchyma) were recovered. The morphological analysis of cuticles and associated palynomorphs reflect the presence of different groups of plants (Bennettitales, Coniferales, Ginkgoales, Polypodiales, and Pteridospermales). In some occasions, cuticles display distinct structures (e.g., monocyclic stomata, secretory structures) that allow comparisons with some extant and fossil genera. We conclude that the study of well-preserved fossil cuticles and associated palynomorphs allow taxonomic inferences on the composition of the parent floras.