Oldest snake fossil shows a bit of leg
Scientists have found fossils of a legged snake with hips a specimen that could be the most primitive snake ever unearthed. The find suggests early snakes were not creatures of the sea and has reignited the debate over how snakes evolved.
Sebastián Apesteguía at the Argentine Museum of Natural History and his team found the snake fossil in a terrestrial deposit in the Río Negro province of north Patagonia, Argentina, in 2003. Unlike a handful of legged fossils found in marine deposits and identified as snakes over the past decade, the new fossil, named Najash rionegrina, has a well-defined sacrum supporting a pelvis and functional hind legs outside of its ribcage.
The creature's skeletal structure suggests it was evolutionarily closer to its four-legged ancestor than previous fossils. And since the scientists found it in a terrestrial deposit, it is near certain that the animal lived on land.
This snake is an important addition because it is the first snake with a sacrum. This represents an intermediate morphology that has never before been seen, says Hussam Zaher, curator of herpetology at the University of São Paulo in Brazil, and part of the research team.
