Rajasthan had lagoons with evergreen vegetation, 55 million years ago, says paleontologists

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Rajasthan is known for the dry geography including the great Thar Desert.  However, it had lush evergreen vegetation with lagoons about 55 million years ago, says a new study, as palentologists have found the fossil of a coconut like fruit from the Kapurdi village in Barmer district of Rajasthan.

Fossil of a 55 million year old fruit Cocos Sahnii from
Kapurdi village in Barmer district of Rajasthan
(White arrows shows the eyes and black ones show ridges)
 Image courtesy: Anumeha Shukla, Rakesh C Mehrotra and Jaswant S Guleria

According to the study which is published in the latest issue of the Journal of Bioscience, the fruit has close relation with the present day coconut palms. It indicates that the environmental conditions in the area were supportive to the growth of coconut like palms which are usually found in the coastal ecosystems with relatively good rain fall, says the study.

“Its presence indicates warm, humid, possibly coastal conditions during the Early Eocene in Rajasthan, in contrast to the present-day dry and desertic climatic conditions occurring there. This finding, along with earlier described evergreen taxa at the site, indicates that the climate of Rajasthan was much better and luxuriant to support the growth of these evergreen taxa”, says the study.

Moreover, the new finding is also in line with earlier studies which have recovered fossils of evergreen vegetation, crabs, fishes, turtles and other aquatic organisms from here, indicating the existence of lagoon like ecosystems 55 million years ago.

According to the study, the uplift of the Himalayas and the Tibetan plateau could be the reasons which have contributed to a drastic change in the environmental conditions of the region, making it dry and arid.

A close relative of today’s coconut

The fruit fossil has two eyes and longitudinal ridges on the surface, making it similar to coconuts. The fibers of the husk are also longitudinally distributed as in a coconut fruit, says the study. Moreover, the 11.7 cm long and 5.8 cm wide fibrous fruit in ovoid shape resembles Cocos nucifera fruit than that of any other subspecies among the coconut palms.

The fruit was earlier identified as Cocos sahnii, when famous botanist Professor Kailas Nath Kaul found its fossil from the same area in 1951. But the study did not scientifically describe the species, as the fossil was an impression of the hard inner layer of the fruit on a stone. However, the new study has analyzed another fossil which has the mesocarp of the fruit (which is similar to the husk of the coconut fruit) intact, to establish its relation with coconut fruits.

Anumeha Shukla, Rakesh C Mehrotra and Jaswant S Guleria of Birbal Sahni Institute of Palaeobotany, Lucknow has conducted the study.