The first snakes appeared some 128.5 million years ago, slithered along the ground but had puny hind legs with complete ankles and toes.
A detailed analysis by Yale University paleontologists uncovered new information into the origin and early history of snakes.
The study published online in the journal BMC Evolutionary Biology concludes the first snakes likely emerged 128.5 million years ago in tropical forests of the supercontinent Laurasia that today includes North America, Europe and Asia. It helps to clear up many debates over the earliest snakes.
"We generated the first comprehensive reconstruction of what the ancestral snake was like," said Allison Hsiang, lead author the study and a postdoctoral researcher in Yale's Department of Geology and Geophysics.
"We infer that the most recent common ancestor of all snakes was a nocturnal, stealth-hunting predator targeting relatively large prey, and most likely would have lived in forested ecosystems in the Southern Hemisphere," said Hsiang.
Hsiang said while snake origins have been debated for a long time, this is the first time these hypotheses have been tested thoroughly using cutting-edge.
"By analyzing the genes, fossils and anatomy of 73 different snake and lizard species, both living and extinct, we've managed to generate the first comprehensive reconstruction of what the ancestral snake was like".
Hsiang and her team identified similarities and differences between the 73 species and used this to create a large family tree for snakes, said Discovery.
Researchers believe that snakes originated on land and not water. They said ancestral snakes were non-constricting foragers that grabbed their prey with needle-like hooked teeth and swallowed them whole.
The emergence of snakes during the Early Cretaceous coincided with the swift appearance of many species of mammals and birds.
"Our analyses suggest that the most recent common ancestor of all living snakes would have already lost its forelimbs, but would still have had tiny hind limbs, with complete ankles and toes. It would have first evolved on land, instead of in the sea," said co-author Daniel Field, a Yale Ph.D. candidate.
"Both of those insights resolve longstanding debates on the origin of snakes."