George Gaylord Simpson.
G. G. Simpson is one of the greatest and most influential palaeontologists of the 20th century for several reasons: the evolution of horses is a very well known example of his work, as well as his contribution on the modern evolutionary synthesis.
I remember though, during palaeontology and/or evolution classes, the professors telling us repeatedly that we had to know and remember Simpson, but without ever telling us precisely why. It was only after a while that I came across one of his books in a little naturalistic bookstore right beside the University of Jussieu. It was an old book, published in French in 1951: “The meaning of evolution”, it was originally published in English in 1949.
First of all it is quite curious and pleasant to see that so shortly after the end of the Second World War the interest in palaeontology and evolution was such that this book was translated and published.
More importantly, while reading it, I realized that almost all of its content was the bigger part of everything that is taught in palaeontology classes (the principle of vicarience, speciation, migrations, the orientation of evolution and its trends, radiations, evolutionary factors and their impacts, …) . Only then did I understand his contribution to modern palaeontology, the importance of his life’s work, and how he established all the bases in the paleontological studies.