Well are 2 sources first in 1910 Dana B. Merrill and Rondônia Federal University saw 25 feet (7.5 m) and later the Wide World Magazine in 1911 and Guinness Book Edition 1978 saw was precise 22 feet (6.70 m)? Rui Mendes Source
For over a century scientists thought the recently discovered northern anaconda (Eunectes akayima) was the same species as the southern anaconda (E. murines). However, a recent genetic study determined northern anacondas diverged from southern anacondas 10 million years ago.