Complex sentence: The specimen was studied by the Australian anatomist Raymond Dart, who was then working at the University of the Witwatersrand in Johannesburg who published his findings in "Nature" magazine in February 1925.
Split into simpler sentences: The specimen was studied by the Australian anatomist Raymond Dart, who was then working at the University of the Witwatersrand in Johannesburg. The first report was published in "Nature" magazine in February 1925.