Spider-tailed horned viper anatomy revealed through X-ray imaging

Researchers have utilized X-ray imaging to uncover the internal structure of the spider-tailed horned viper (Pseudocerastes urarachnoides), a rare species native to the Zagros Mountains in Iran. The study, published in The Anatomical Record, examines the unique vertebrae at the tip of the snake's tail, which mimics the appearance and movement of a spider to lure avian prey.

Historically, the tail's unusual shape was often mistaken for a tumor, parasite, or anomaly. While a specimen collected in 1968 serves as the species' holotype at the Field Museum, it was not until another individual was found in 2003 that scientists recognized the spider-like tail as a standard characteristic of the species. The new research provides a detailed look at how this specialized anatomy is constructed.