6 April 1951
Archaeologist Dr. Robert Broom died at the age of 84. In 1947 he discovered 'Mrs Ples', the 2 million year old skull that is believed to be a distinct relative of humankind.
References
Dr Thackeray.F,"Mrs Ples" and our distant relatives,from Science in Africa,[online],Available at www.scienceinafrica.co.za [Accessed: 3 April 2014]