Quote Originally Posted by Stefan-A View Post
The evolution of the snake from lizards, which also have the gene as you mentioned (meaning that venom actually predates snakes) to a more subterranean lifestyle would suggest that constriction probably wasn't the first method and it certainly wouldn't be a practical one under those conditions. Venom on the other hand would be. Constriction probably wouldn't have been a solution until the snakes started to return to the surface.

But you are definitely right about boids coming early and viperids etc. being a more recent "invention".
I stand corrected. Thanks Stefan. Makes complete sense.