Trilatiporate pollen from Indian Palaeogene and Neogene sequences: evolution, migration and continental drift

Abstract

The diagnosis of the genus Dorreenipites Biswas, 1962, incorporating heteropolar pollen with sub-equatorial pores, is emended to include morphological details observed on pollen recovered from the Miocene lignite, Neyveli, Tamil Nadu, India. A new genus Retitrilatiporites is proposed to assimilate trilatiporate pollen from Palaeocene-Eocene sediments of Kutch, which are distinct in having feeble pore-bearing projections, ± equatorial pores, and a smaller size. A speciation scheme for both trilatiporate genera is proposed based on significant morphological features, namely well-developed vs. feeble pore-bearing projections, and exine structure varying from psilate to reticulate on one or both poles. Evolutionary trends of these taxa in Africa and India and their stratigraphic significance are discussed, from the perspective of their migration and extinction, which was controlled by the northward drift of the Indian plate. Four new species and five new combinations are proposed, and the botanical relationship of this pollen type is discussed.