In the arid, inhospitable climate of western Iran’s Zagros Mountains, life has found a remarkable way to survive.
Circling above, a bird glimpses what at first glance looks like a plump spider climbing on the rocks. But as the avian predator swoops in, it becomes the prey as something that initially appeared to be a rock moves to snap it up.
The roughened rock is actually the bumpy surface of a viper with hornlike features on its head — and the “spider” is the tip of its tail, flicking with tantalizing movement.
When scientists collected a specimen of the spider-tailed horned viper in Iran in 1968, they disregarded the arachnid-shaped tail tip.
“Everybody who looks at the tail thinks it has a tumor or some sort of growth or a parasite on it, and that it’s some sort of anomaly,” said Sara Ruane, associate curator of herpetology and director of core laboratories at the Field Museum’s Negaunee Integrative Research Center in Chicago. “And it wasn’t until another individual was collected in 2003 that somebody thought, ‘You know, maybe this is the norm for this species.’”
