NEW DELHI: Scientists in India have begun fresh excavation and preservation of petrified wood fossils at Mandro Park in Jharkhand, 70 years after it was dug up while saying fresh efforts are required to establish how Australia Antarctica had split from India and non-flowering plants led to birth of flowering plants (angiosperms) during the early Cretaceous period.
The study is being led by Birbal Sahni Institute of Paleosciences (BSIP) and forest officers of Jharkhand. The area under excavation includes Damin-i-Koh in the Rajmahal Hills of Mandro Park and primarily Sahibganj, Pakur, Dhumka and Godda districts of Jharkhand.
"There are three parts to this big research. We will collect sediments from section from where we procure the fossil. The sediments are then used for determining the biostratigraphic framework which in turn helps us to determine the age of the fossil" said scientist Dr Vivesh Vir Kapur, BSIP, who is leading the research.
"Then we try to recover pollens, known as palynomorphs, from the rock samples and also from where wood fossils have been recovered. The process is used to separate palynoflora and microfauna," said second scientist Dr Suresh Pillai.
Petrified woods are a form of wood where the minerals replace the structure of the organism. More than four dozen fresh fossils have been dug up already between March 9 and 13 this week.
There were a large specimens that lay buried about 1m into the ground which demand in-situ conservation and careful extraction near , said scientists.
So, when a prehistoric plant is found on both, for instance, Australia, and India, it would help understand the split better. “The flora during the Cretaceous period was largely conifers and non-flowering plants. Flora from Antarctica and Australia are similar to that from India. Research will help us narrow down the time frame when they separated from India. Right now, it is believed to have happened 140 million years ago,” said Dr Vandana Prasad, director of the institute.
The Cretaceous period (145 to 65 million years ago) is believed to have had warm climate and high sea levels. The first flowering plants on the planet began to emerge in the Early Cretaceous period, 125 million years ago.
“They began to diversify during Late Cretaceous period (by 65 million years ago). This rapid expansion of angiosperms (flowering plants) corresponds to an important phase in the breakup of Gondwana (the supercontinent from which India, Sri Lanka, Australia, South America, Africa, Arabia, Madagascar and Antarctica broke off) and a series of major sea-level fluctuations,” said a senior archaeologist working on the project.
Prasad added, “It was the founder of our institute, Birbal Sahni, who had between 1946 and 1948 first discovered numerous specimens of petrified wood (in which minerals replace the structure over time). Ever since then, it has been the site of discovery of many Cretaceous fossils.”