Journal of Environmental Biology

Cuticle bearing fossil leaves from Mio-Pliocene period in the

Sub Himalayan zone and its phytogeographical  and
environmental implications

 

Mahesh Prasad¹, E.G. Khare¹, A.K. Kannaujia²* and Alok³

¹Birbal Sahni Institute of Palaeobotany, Lucknow-226 007, India

²Department of Botany, Lucknow University, Lucknow-226 007, India

³Department of Botany, Allahabad University, Allahabad-211 002, India

*Corresponding Author email : ankit_kannaujia24@yahoo.com 

 

 

 

  Publication Data

  Paper received:

  03 July 2012

 

  Revised received:

  31 December 2012

 

  Accepted:

  25 January 2013

 

Abstract

A variety of fossil leaves were collected from the Siwalik group of India and Nepal. Few of them possessing sufficient cuticle were identified on the basis of morphological and cuticular features (epidermal cells, stomatal density, stomatal index etc). They closely resembled with the extant taxa, Pterospermum acerifolium (Sterculiaceae), Dichapetalum gelonioides (Dichapetalaceae), Paranephelium macrophyllum, P. xestophyllum (Sapindaceae), Gluta renghas (Anacardiaceae) and Mimusops elengi (Sapotaceae). The habit, habitat and present day distribution of the above modern comparable taxa suggest the prevalence of tropical humid environment during deposition of Siwalik sediments in the Sub–Himalayan zone. The extinction of the above comparable taxa (except Pterospermum acerifolium) from the Sub-Himalayan zone indicates the environmental change after Mio- Pliocene time. The epidermal and stomatal features of the fossil leaves collectively suggest the existence of  a broad leaved mesophytic forest at low altitude having comparatively high humidity all along the Himalayan foot hills during 8-12 million years ago.

 

Key words

Foliar epidermal architecture, Fossil leaves, Morphology, Phytogeography, Sub-Himalayan zone

 

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