First Fossil Mallow Flower from Asia

Abstract

Premise of research. Malvaceae, or the mallows, are well known from the Cenozoic sediments of Asia and are represented by many fossil leaves, woods, fruits, and pollen. Until now, no fossil flower of Malvaceae has been reported from the Cenozoic sediments of Asia. The present study addresses this lacuna and documents the evidence of mallow fossil flowers from Asia for the first time. Methodology. Fossil flowers similar to modern flowers of Bombax L. (Malvaceae) were recovered from the latest Neogene (Pliocene) sediments of Chotanagpur Plateau, Jharkhand, eastern India. They were revealed by careful removal of the overlying matrix and studied under light microscopy. Pivotal results. The fossil flowers, characterized by irregularly lobed sepals, obovate-elliptic petals, numerous stamens bearing long filaments, and characteristic reniform anthers, are recognized as a new species, Bombax asiatica Hazra, Bera et Khan sp. nov. A morphological principal coordinates analysis and cladistic parsimony analysis based on floral morphological characters support this taxonomic assignment. Conclusions. This fossil evidence provides an important clue about the past diversity and paleobiogeography of the mallow family in the Indian Cenozoic. This finding and earlier reported Malvaceae fossils from the same locality also indicate the presence of tropical climate in Jharkhand, eastern India, during the time of deposition.