1Department of Botany, Shivharsh Kisan Post Graduate College, Basti, U.P. 272001, India
2Department of Botany, M.L.K. Post Graduate College, Balrampur, U.P. 271201, India
3Department of Botany, S.K.B.B. Govt. P.G. College, Harakh, Barabanki, U.P., India
4Birbal Sahni Institute of Palaeosciences, 53, University Road, Lucknow-226007, India
Applied Ecology and Environmental Sciences.
2022,
Vol. 10 No. 6, 346-359
DOI: 10.12691/aees-10-6-4
Copyright © 2022 Science and Education PublishingCite this paper: Gopal Ji Kushwaha, Shivendra Mohan Pandey, Ravi Krishna Mishra, Alok , Mahesh Prasad. Plant Macrofossils from Churia Formation (Miocene) of Koilabas Area in the Himalayan Foot Hills of Western Nepal and their Palaeoclimatic Consideration.
Applied Ecology and Environmental Sciences. 2022; 10(6):346-359. doi: 10.12691/aees-10-6-4.
Correspondence to: Gopal Ji Kushwaha, Department of Botany, Shivharsh Kisan Post Graduate College, Basti, U.P. 272001, India. Email:
gopalbot@gmail.comAbstract
Palaeobotanical study on the plant macrofossils from Lower and Middle Churia Formation (Miocene) of Koilabas area, western Nepal has revealed the presence of 116 species belonging to 83 genera of 33 angiospermous families. They are mainly based on leaf-impressions and a fruit and seed. The family Fabaceae is the most dominant family represented by 21 species in this assemblage followed by Annonaceae (10 species), Dipterocarpaceae, Sapindaceae and Anacardiaceae (6 species) and Combretaceae, Rubiaceae, and Moraceae (5 species). Fabaceae which appeared in Upper Paleocene became a major constituent of the evergreen forest during Miocene times all along the Himalayan foot hills. The predominance of evergreen and moist deciduous taxa in this fossil assemblage indicates the prevalence of tropical warm humid climate with plenty of rain fall during the Miocene. The present-day distribution of comparable modern species of all the fossils recovered from Koilabas area indicates that they are mostly known to occur in South east Asia, Indo-Malayan and North-east Indian regions, wherever favorable climatic conditions exist. Most of the taxa represented in the fossil assemblage do not occur in the Koilabas area or all along the Himalayan foot-hills of both India and Nepal. This obviously indicates that changes in the climate must have taken place after the deposition of Siwalik sediments in the Koilabas area. Study of the structural features of fossil leaf-impressions suggests that the Koilabas area in the Himalayan foot-hills of western Nepal enjoyed a tropical climate along with plenty of rainfall during the Miocene times. Coexistence /Nearest Living Relative (NLR) method further suggests that the area enjoyed a tropical climate with the Mean Annual Temperature (MAT) 23-30°C and Mean Annual Precipitation (MAP) 2400-3600 mm) during the Miocene.
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