The original snake ancestor was a night-time predator that moved around on tiny hind limbs that included ankles and toes.
A massive analysis of snake and lizard species revealed for the first time that these critters evolved on land, and not in the sea as was popularly believed, BioMed Central reported. A team of researchers analyzed the fossils, genes, and anatomy of 73 snake and lizard species, and linked snakes' common ancestor to warm forest in the Southern Hemisphere around 128 million years ago.
"While snake origins have been debated for a long time, this is the first time these hypotheses have been tested thoroughly using cutting-edge methods. 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," said lead author Allison Hsiang.
The researchers pinpointed similarities and differences between the studied species, allowing them to construct a revealing family tree outlining their evolution. The earliest snake ancestor was believed to have been a nocturnal animal that targeted soft-bodied vertebrate and had tiny back "legs." Most ancestral reptiles are believed to have hunted during the day, so this species is believed to have been an anomaly. The ancient snake most likely transitioned into a diurnal (day time) lifestyle between 45 and 50 million years ago when the Colubroidea emerged, which is the family of snakes that make up over 85 percent of the species alive today.
The study suggests the impressive success of snakes throughout history is a result of their skills as "dispersers." Snakes can travel ranges up to 110,000 square kilometers, which is an area about 4.5 time larger than what can be accomplished by lizards. They can also move through environments that are generally not hospitable to dispersal, such as aquatic habitats.
The findings were published in a recent edition of the journal BMC Evolutionary Biology.
