Fossils and tech offer new clues to snake origins

New York: Scientists believe the ancestors of today’s snakes emerged around 160 million years ago, yet the earliest members of the family tree remain a mystery — their fossils still undiscovered.

That gap leaves key questions unanswered: what the first snakes looked like, where they got their start, and who their closest relatives are.

One leading idea comes from evolutionary biologist Marc Tollis of Northern Arizona University. He envisions early snakes as skinny burrow-hunters in the age of dinosaurs, squeezing into mammal holes to prey on the furred creatures hiding underground. The fossil record for snakes is “long and thin,” Tollis says, with major gaps in their history. What is clear is that starting about 125 million years ago, snakes used their flexible body plans to diversify rapidly, eventually spreading across six continents and into the Indian and Pacific Oceans.

Now, new fossil finds combined with modern technology — including CT scans and genetic analysis — are helping researchers fill in the blanks. By comparing bone structures and DNA of living species with rare fossil fragments, scientists hope to pinpoint when and how snakes lost their legs and gained their signature slither.