Why is it said that snakes evolved from lizards?

 The lizard is the ' great grand father ' of snake. Snakes evolved from lizards millions of years ago. There is  a confusion regarding the group of lizards from which the snake evolved. Scientists depend on fossils to study evolution. A snake does not make a good fossil. Only piece of backbone, and the odd skull in poor condition have been found. The most primitive living snakes are burrowers. Therefore, some scientists believe that snakes arose from burrowing lizards which had much reduced limbs. others think that snakes evolved in the sea. 

    SNAKE FOSSIL

 There is a super family of non burrowing lizards known as PLATYNOTA , and many scientists believe that lizards rose from  this super family. The GILAMONSTER , BEADED LIZARD and a poisonous lizard called LANTHANOTUS belong to this family. 

PLATYNOTA

GILAMONSTER

BEADED LIZARD

LANTHANOTUS

Members of this family do have some features in common with snakes. The backbone and the tongue of these lizards , and the snakes are similar in shape. The two halves of the lower jaw are not firmly joined. However, the eye of the snake is specialized ; quite unlike the eye of an non borrowing lizard. Scientists point out that the primitive platynotans may themselves have been burrowers. So , lizards belonging to the super family platynota are regarded as the    'Great Grandfathers' of snakes.

                    pictures source : Google image ; “no copyright infringement is intended”