Asteroid wiped out reptile species
Lizards and snakes as well as dinosaurs were killed off by an asteroid which struck Earth 65 million years ago, a study has shown.
The massive impact off the coast of Mexico wiped out up to 83% of the reptiles, scientists believe.
Bigger species suffered most, with no species weighing more than around one pound surviving.
Experts who studied the fossil record of lizards and snakes in North America found evidence that the asteroid cataclysm was more devastating than previously thought.
"The asteroid event is typically thought of as affecting the dinosaurs primarily," said lead scientist Dr Nicholas Longrich, from Yale University in the US. "But it basically cut this broad swathe across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard."
A remarkable range of reptile species lived during the last days of the dinosaurs, said the scientists writing in the journal Proceedings of the National Academy of Sciences. They included tiny lizards and others up to six feet long which hunted prey in the swamplands of what is now Montana.
"Lizards and snakes rivalled the dinosaurs in terms of diversity, making it just as much an 'age of the lizards' as an 'age of the dinosaurs'," said Dr Longrich.
Among the most diverse lizard branches to vanish was the Polyglyphanodontia, a large family including up to 40% of all lizards then living in North America.
While examining the fossil collections, the scientists came across an unnamed member of this group which they called Obamadon gracilis. The name is derived from US president Barack Obama and the Latin for tooth and slender.
"We're just having fun with taxonomy," said Dr Longrich.