Percy M. Butler

Percy Milton Butler (19 July 1912 – 7 February 2015)^[1] was a British zoologist and palaeontologist. He proposed that dental characters are expressed in morphogenetic gradients along the dentition, which could therefore be used to study evolution. This became known as Butler's Field Theory. He was Professor of Zoology at Royal Holloway, University of London, where he was the Head of the Department of Zoology from 1956 to 1972, and where he established the first course on mammalogy in the UK.