Bombacaceae pollen from the Indian Tertiary sediments and its bearing on evolution and migration

Several pollen species recovered from the Indian Tertiary sediments have close similarities with pollen of extant Bombacaceae. These morpho species are included in the morphogenera Lakiapollis Venkatachala and Kar, Dermatobrevicolporites Kar, Bombacacidites Couper, Tricolporocolumellites Kar and Retitribrevicolporites Kar. Nine species are re-described on the basis of original type material or other specimens. The fossil pollen belongs to the Bombax- and Durio-types. The small-sized Bombax-type pollen (e.g., Eriotheca pollen) has been documented in India from the early Palaeocene to the Miocene while large-sized pollen similar to that of Bombax appeared in the Oligocene and continued up to the Present. The lobed variety of the Bombax-type is rare and occurs only in the Pleistocene. Palynological evidence suggests a migration of Bombacaceae producing Bombax-type pollen to India from Africa. Durio-type pollen appeared in the late Palaeocene and continued to dominate until the early Eocene. In southern India, this pollen remained frequent during Oligocene/Miocene times, whereas in other areas, it became rare at the end of the Eocene. The earliest (late Palaeocene) record suggests an origination of Bombacaceae producing Durio-type pollen in India and a subsequent migration to Southeast Asia.