His specialist knowledge of mammalian dentition led him to pursue the same path with regard to human evolution and he came to be regarded as the world's leading expert on the evolution of human dentition, a reputation secured by the 1922 publication of The Evolution of the Human Dentition.
His deep understanding of mammalian dentition influenced his research on human evolution, positioning him as a preeminent expert on human dentition. This recognition was further solidified by his influential 1922 publication titled "The Evolution of the Human Dentition."