Complex sentence: He studied lemurs and the insectivorous primates, as always concerning himself with evolutionary origins, and from the 1920s became involved in the study of marsupials, in 1947 developing his "palimpsest" by showing a connecting between the monotremes and early reptiles.
Split into simpler sentences: He studied lemurs and the insectivorous primates, as always concerning himself with evolutionary origins. From the 1920s he became involved in the study of marsupials, in 1947 developing his "palimpsest" by showing a connecting between the monotremes and early reptiles.