How many Different Groups of Reptiles are there in the World?

There are only four main groups of reptiles left on earth:

Crocodilians, snakes and lizards, turtles and tortoises, and the tuataras, an old lizard form found in New Zealand.

All of them run the risk of extinction due to human encroachment, and due to humans wanting to turn them into pets, food, and ornaments.

Of these, the snakes are at greatest risk.

In fact, snakes may be the most at-risk group for extinction of all vertebrates, not just reptiles.