\u201cIt sat on the shelves of the museum for decades,\u201d explains Sara Ruane, Associate Curator of Herpetology at the Field Museum, \u201cbut it wasn\u2019t until another specimen with a similar tail was found in 2003 that people revisited it.\u201d<\/p>\n
It was theorised that the tail, which has a series of \u2018spiders-leg\u2019 appendages and a bulb-shaped tip, had evolved to be used as a lure with which to attract prey.<\/p>\n
In 2008, footage was recorded in the wild of the snake behaving in this precise manner. As the viper remained still,\u00a0camouflaged\u00a0against a rocky outcrop, it tweaked the very tip of the tail in a provocative, figure-of-eight pattern, mimicking the movement of a\u00a0spider. This movement increased with the presence of potential prey, and birds such as Isabelline shrike and several warbler species have been recorded trying to \u2018catch\u2019 the spider only to be caught themselves by the\u00a0snake.<\/p>\n
\u201cThe appendage at the end of its tail is so outrageous, I remember thinking it was so cool. It\u2019s truly unique among snakes.\u201d Ruane added.<\/p>\n The study, published in the journal\u00a0The Anatomical Record<\/em>, details the collaborative efforts of Ruane and Georgias Georgalis, an associate professor at the Polish Academy of Sciences in Krak\u00f3w.<\/p>\n They made use of a new X-ray Computed Technology (XCT) Laboratory at the Field Museum to produce a 3D rendering of the tail from that original spider-tailed horned viper specimen.<\/p>\n \u201cWith the spider-tailed horned viper, we were particularly interested in seeing what the vertebrae at the tip of the tail look like, because the exterior of this snake\u2019s tail is so unusual,\u201d explained Georgalis, who, as a palaeontologist, has a particular interest in the physical appearance of an animal beyond what may be learned from skeletal remains.<\/p>\n \u201cIt turned out that the spider tip on the tail is only external morphology \u2013 the tail vertebrae themselves were typical of most vipers,\u201d Georgalis continued, \u201cThere was nothing in the snake\u2019s skeleton that would suggest how extreme its tail looks on the outside.\u201d<\/p>\n Having determined that the tail bones of\u00a0Pseudocerastes urarachnoides<\/em>\u00a0are typical of a viper species, the researchers hope that their findings will provide groundwork for further research into the external tissue structure of the spider-like lure.<\/p>\n