First fossil record of mulberry from Asia

Although Asia shows moderate species richness of mulberry (Morus L.) today, unfortunately no mulberry fossil has been reported from the Cenozoic sediments of this continent to date. Here, we report for the first time the occurrence of leaf remains (both impression and compression) having similarity with modern leaves of Morus from the early Eocene sedimentary sequences of the Gurha opencast lignite Mine, western Rajasthan, India. The fossil specimens characterized by a heart-shaped ovate lamina, cordate base, long petiole, crenate-serrate margin, actinodromous nature of primary veins and craspedodromous type of secondary venation pattern are recognized as Morus asiatica Patel, Rana and Khan sp. nov. This record suggests that mulberry was an important component of tropical-subtropical evergreen forests growing in a warm humid climate in the area of northwestern India during the Eocene. This taxon subsequently declined from the local present-day dry and desertic vegetation probably because of the drastic climate and latitudinal change in the area, related to the Himalayan Orogeny and rainfall seasonality since the Eocene. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study reports the fossil leaf remains of Morus from the early Eocene sediments of India, indicating the presence of tropical-subtropical evergreen forests in the region during that time. However, due to drastic climate and latitudinal changes, mulberry declined from the present-day vegetation in the area.