Vipers evolved either nose or eye horns depending on their habitat

The horns on vipers’ eyes could help camouflage their head in rocky areas or trees, while those with nose horns may blend in better on forest floors
The small horns that stud the heads of many viper species may play a role in camouflage, suggesting they evolved as a result of the varying environments the snakes inhabit.

Theo Busschau and Stéphane Boissinot at New York University Abu Dhabi in the United Arab Emirates studied whether horn evolution in these reptiles could be tied to environmental factors by analysing the physical features of 263 viper species to determine their evolutionary relationships to each other. They also compared horn placement – over …