[ClearCase_guy]

Their land-based lifestyle, including burrowing underground at least some of the time, may be the reason. "Having limbs is a real problem if you need to fit through small openings underground

Land-based lifestyle? Are limbs somewhat rare among land-based creatures? And the burrowing part? I guess that explains why moles and prairie dogs have no limbs.

As usual, close to 100% guesswork, culminating in a conclusion. The "science" of evolution.

[ZULU]

Snakes and lizards are VERY closely related. They are connected EVOLUTIONARILY as this study indicates.

There are limbless burrowing lizards and their are snakes like boas which have tiny, rudimentary limbs called "spurs" located at the rear of the body. Both snakes and lizards have scales - a feature absent in Crocodilians and Turtles.
Burrowing snakes and limbless lizards have many simialr behavioral patterns and ecological requirements. Osteologically, snakes and lizards are very similar.