Prior to this research, the captivating new vipers, now recognized as among the most alluring ever found, were mistakenly classified as part of a single, highly variable species spanning from Mexico to northwestern Peru. The decade-long study began with an unexpected incident wherein one of the authors was bitten by one of these previously undiscovered species.

Eyelash vipers stand out due to a distinctive feature: a set of enlarged spine-like scales positioned atop their eyes. These "lashes" bestow upon the snakes a formidable and fierce appearance, yet the true purpose of this feature remains unknown. What is definite, however, is that certain populations exhibit longer, and more stylized eyelashes compared to others. The variations in the condition of the eyelashes led researchers to hypothesize the existence of undiscovered species.

Eyelash vipers are also famous for another feature: they are polychromatic. The same patch of rainforest may contain individuals of the turquoise morph, the moss morph, or the gold morph, all belonging to the same species despite having an entirely different attire. "No two individuals have the same coloration, even those belonging to the same litter (yes, they give birth to live young)," says Alejandro Arteaga, who led the study.

For some of the species, there is a "Christmas" morph, a ghost morph, and even a purple morph, with the different varieties sometimes coexisting and breeding with one another. The reason behind these incredible color variations is still unknown, but probably enables the vipers to occupy a wide range of ambush perches, from mossy branches to bright yellow heliconias.