I second Hamster_of_Borg's recommendation, Greene's book, "Snakes, the evolution of mystery in nature", is IMHO, an outstanding book. I've read and re-read it several times. I covers various aspects of the evolution of snake systematics, not only ancestors, but the evolution of venom, delivery of same and on and on. Worth every penny, which I think I found it used for $18.00 USD.
Rome did not build a great empire by having meetings, they did it by killing all who opposed them.