Modern reptiles evolved from the dinosaurs. Snakes evolved from legged reptiles, losing their legs to conserve energy.
Reptiles evolved from amphibians. Amphibians evolved into mammals and birds. The fossil evidence proves this.
The Facts Are .....
Dinosaurs like all other fossil animals appear in the fossil record intact, without predecessors, and without ancestors after their extinction. There are similarly no intermediate dinosaurs between the first small ones and the giant varieties, as the theory of evolution would dictate. Creation Ex Nihilo, Vol. 10, No. 2, 1988
"Unfortunately not a single specimen of an appropriate reptilian ancestor is known prior to the appearance of true reptiles. The absence of such ancestral forms leaves many problems of the amphibian-reptilian transition unanswered." Written by evolutionist Robert L. Carroll in his article "Problems of the Origin of Reptiles", in Biological Reviews of the Cambridge Philosophical Society, Vol. 44, No. 3, July 1969 p:393
"Each species of mammal-like reptile that has been found appears suddenly in the fossil record and is not preceded by the species that is directly ancestral to it. It disappears some time later, equally abruptly, without leaving a directly descended species ....." Written by evolutionist Dr Tom Kemp (Curator of Zoological Collections, Oxford University Museum, England), in his article "The Reptiles that Became Mammals" in New Scientist, Vol. 92, No. 4, 1982 p:583
An examination of the myriads of reptilian fossils, especially the massive numbers found on the Swiss-Italian border, give no clue to their evolution. One palaeontologist has said about this dilemma,
"Why, given the wealth of fossil material, should the evolution of reptiles prove so evasive? .....
deciphering the past is not an easy task." Reptilian fossils do not give any of the hoped-for clues to how they fit into the scheme of evolution, despite reptilian evolution being spoken about as a fact.
Scientific American, June 1989 p:50-57
Scientists at the University of California have tested the snake energy advantage theory by measuring the metabolism of snakes which wore tiny oxygen masks as they slithered on treadmills.
The scientists concluded that the evolutionary prediction was false as limbless movement did not conserve energy. San Francisco Examiner, August 12, 1990