Identifying the World Famous Palaeobotanist

The question asks us to identify a world famous Palaeobotanist from the given list of renowned Indian scientists. Palaeobotany is the branch of botany that deals with the study of fossil plants. A Palaeobotanist studies plant life of the geological past, using fossil remains.

Let's look at the options provided:

• Prof. S.R. Kashyap: He was a renowned Indian botanist, primarily known for his work on liverworts and mosses (Bryophytes). While a significant figure in botany, he is not primarily known as a Palaeobotanist.
• Dr. J.C. Bose: Sir Jagadish Chandra Bose was a polymath, physicist, biologist, botanist, and archaeologist. He made pioneering contributions to the study of radio and microwave optics, plant science, and founded the Bose Institute, Kolkata. He is not primarily known as a Palaeobotanist.
• Prof. Birbal Sahni: Prof. Birbal Sahni was an Indian paleobotanist who studied the fossils of the Indian subcontinent. He is considered the father of Indian paleobotany. His work on the fossil flora of India is internationally recognized, making him a world famous Palaeobotanist. He founded the Birbal Sahni Institute of Palaeosciences in Lucknow.
• Prof. K.C. Mehta: Prof. K.C. Mehta was a distinguished Indian plant pathologist, known for his extensive research on rusts of wheat. He made crucial contributions to agriculture but was not a Palaeobotanist.

Based on their fields of expertise and international recognition for their work in fossil plants, Prof. Birbal Sahni is the individual on the list who is a world famous Palaeobotanist.

Prof. Birbal Sahni's significant contributions to the study of fossil plants, particularly from the Gondwana period in India, established him as a leading figure in paleobotany globally. His research helped in understanding the ancient plant life and geological history of the region. Thus, he is recognized as a world famous Palaeobotanist.

In summary, distinguishing between these prominent scientists requires understanding their primary fields of research. While all were important figures in Indian science, only Prof. Birbal Sahni specialized in the study of fossil plants, qualifying him as a renowned Palaeobotanist.