EDMONTON, Alberta, Jan. 27 (UPI) -- The previous oldest snake fossils were recovered from 100-million-year-old sediments. Paleontological evidence suggested snakes exploded onto the animal scene around that time.
But new findings -- a series of newly identified snake skulls -- set the evolutionary origins of the modern snake back an extra 70 million years, suggesting that between 170 and 100 million years ago, early snakes were slowly evolving into the creatures we see and recognize today.
The findings are not the result of newly unearthed bones, but of a reanalysis of old fossils by an international team of scientists -- fossils previously associated with other non-snake lizards. But a reinterpretation of these fossils, including a range of specimens from Europe and North America, suggests snakes didn't just show up out of nowhere. Instead, their evolutionary timeline extends farther back than previously thought, a timeline now possessed of large gaps that will need to be filled with future research.
"Based on the new evidence and through comparison to living legless lizards that are not snakes, the paper explores the novel idea that the evolution of the characteristic snake skull and its parts appeared long before snakes lost their legs," explained Michael Caldwell, a professor at the University of Alberta in Canada.
"The study explores the idea that evolution within the group called 'snakes' is much more complex than previously thought," Caldwell added. "Importantly, there is now a significant knowledge gap to be bridged by future research, as no fossils snakes are known from between 140 to 100 million years ago."
The new study was published this week in the journal Nature Communications.