A semi-ring porous fossil wood of Ziziphus from the Late Tertiary of Rajasthan

Abstract

A fossil wood of Ziziphus Mill. showing semi-ring porosity has been reported from the outskirts of Bikaner city, Rajasthan. It belongs to the Mar Formation, age of which most probably is Pliocene. Although fossil leaves and fruits of Ziziphus are known, there is no authentic record of its fossil wood so far. Thus the present report forms the first definite record of a fossil wood of Ziziphus. The fossil has provided evidence that ring-porosity is not a modern phenomenon in ziziphus, but most probably it is a genetically controlled character and not the result of adaptation to any cooler climate as has been envisaged the cause of ring porousness in woods by some workers.