FOSSIL FRUITS AND SEEDS OF ZINGIBERALES FROM THE LATE CRETACEOUS-EARLY CENOZOIC DECCAN INTERTRAPPEAN BEDS OF INDIA

Premise of research. Fossil fruits and seeds of Zingiberales provide essential data on the past diversity and distribution of the order, augmenting our understanding of the evolutionary history of gingers, bananas, and relatives. Methodology. Three different types of zingiberalean fruits and seeds from the Late Cretaceous-early Cenozoic Deccan Intertrappean beds of central India were studied using physical sections, polished slices, peels, and micro-computed tomography scanning. A morphology-based phylogenetic analysis was conducted to assess the fossils' phylogenetic position within Zingiberales. Pivotal results. Fruits and seeds of Musa cardiosperma Jain were reevaluated, and newly collected specimens indicate that this species was common and widely distributed across central India during the late Maastrichtian. Morphological differences indicate that they do not conform to the extant genus Musa but instead represent an extinct genus of Zingiberaceae for which the name Momordiocarpon R.N. Deshmukh & Kokate has priority. Seeds of Momordiocarpon cardiospermum (R.K. Jain) comb. nov. lack the micropylar collar found in extant Musaceae and have only a weakly defined oblique chalazal chamber. Orthogonospermum patanense gen. et sp. nov. is recognized based on seeds from the Maastrichtian of Marai Patan. These seeds are rectangular, with 90 degrees corners in transverse and sagittal sections, and are obovate in coronal section. Both Momordiocarpon and Orthogonospermum have massively thickened seed coats in the hilar region, unlike any extant Zingiberales. Phylogenetic analyses place Momordiocarpon and Orthogonospermum in Zingiberaceae. Callistemonites indicus Bande, Mehrotra & Prakash, known from fruits with intact seeds from the Paleocene of Ghughua, is here shown to represent a taxon distinct from M. cardiospermum; its original binomial is reinstated. Conclusions. Together, these three species add to the known diversity of the Late Cretaceous and early Cenozoic of India. Two of these species are confirmed to be in Zingiberaceae, enhancing our understanding of the early diversification and biogeographic spread of Zingiberales.

Automated summary

This study analyzed three different types of fossil fruits and seeds of Zingiberales from the Deccan Intertrappean beds of central India, revealing that two of them belong to the Zingiberaceae family, enriching our understanding of the early diversification and biogeographic spread of Zingiberales.