Snakes evolution discovered? And what does this mean for other cryptids?

Land not sea' origin for snakes

One of the most primitive snake fossils ever found hints that the slithery reptiles might have originated on land, not in the sea as has been proposed.The animal, which lived at the same time as the dinosaurs, probably emerged from a line of burrowing reptiles that lost their legs.

Where and how snakes diverged from their legged cousins the lizards has been a mystery.Details of the find appear in the journal Nature.
The debate over snake origins has been complicated by the scarcity of transitional fossils (those with features in between two groups of creatures).But new fossils from eastern Wyoming, US, belonging to the ancient snake Coniophis precedens - which lived some 65-70 million years ago - could help clear up the mystery.According to the analysis by Nicholas Longrich from Yale University and colleagues, Coniophis lived in a floodplain environment and "lacks adaptations for aquatic locomotion".
Read rest see pics here: http://www.bbc.co.uk/news/science-environment-18998634

This set me thinking.....What if lake creatures were originally land dwelling animals that evolved to go back into the water? It would explain how they could be a species that has not been discovered before and that they live in the bottom of the lakes normally, only rising to be seen occasionally. The Ice Age could have forced them to change, their landscape being torn apart by the ice. Just a thought for the weekend ...(the question would be what did they evolve from/). Any ideas please post in the comments section.