I was curious as to where I read that from and now I know. It was from Renee or Jesus. Anacondas have the largest sexual dimorphism among tetrapods. Four legged vertebrates. Tetrapods include amphibians, reptiles, mammals, etc. Although snakes and some lizards have lost their four legs because of their ancestry they are still considered tetrapods.

Source: http://pages.prodigy.net/anaconda/research.htm

Arik