The fossil of a small lizard that lived in the Early Cretaceous period 150 million years ago was discovered recently. It is unique because it has extended ribs covered with a membrane that it may have used as wings to glide. Dubbed Xianglong zhaoi, its fossil was described by Xing Xu of the Shenyang Normal University in China. Judging from its immature "feathers," it had died young. Birds are now thought to have originated from dinosaurs.
Birds use "arm" bones to fly and flap their wings in the air. Unlike them, the lizard may have simply extended its ribs outwards when jumping between trees, much like flying squirrels do today. They may have used their forelimbs to grasp onto things upon landing.