Scorpions are certainly one of the most impressive animals on Earth. In particular the amazing stinger laden tail is just plain awesome. This is what a killer robot should look like! Even among the family of arthropods, famous for amazing their bodies, legs, and wings, scorpions are unique.
This summer researchers from Europe report a detailed “engineering” study of how the scorpion’s tail works [1]. it’s pretty cool.
“Some constructional features seem to be noteworthy from an engineering point of view. “
(From [1], p.5)
First of all, it’s not technically a “tail”, it’s an elongated section of the body called a “metasoma”. It is not only articulated like an appendage, but contains parts of the digestive and nervous system. It is incredibly agile, flexible in three dimensions, bending and twisting, and capable of extending over the body to reach in front of the head.
The new study performed detailed CT scans of scorpion tails and created a 3D model. The model was studied in a CAD system, which reveals how the articulation works. And naturally, this model could be 3D printed to create an artificial scorpion tail.
The scorpion’s joints are complicated, “perhaps best be described technically as a ‘sliding rolling pair’ on each side, left and right, or altogether, since the contact areas of joined segments are used simultaneously for sliding and rolling.” ([1], p. 5) They have no easy comparison to other insect appendages (and it’s not actually an appendage, anyway).
The scorpion’s tail, the metasoma, raises interesting questions about how the body evolved this form. It is interesting that these body sections evolved to be function very like an appendage.
“It is the only known case in which an entire body section has been modified to perform tasks similar to that of an appendage while maintaining the digestive function.”
([1], p.7)
Neat.
- Alice Günther, Manfred Drack, Lionel Monod, and Christian S. Wirner, A unique yet technically simple type of joint allows for the high mobility of scorpion tails. Journal of The Royal Society Interface, 18 (20210388) September 1 2021. http://doi.org/10.1098/rsif.2021.0388
- Sabrina Imbler, How Scorpion Tails Do the Bend and Twist, in New York Times. 2021: New York. https://www.nytimes.com/2021/08/31/science/scorpion-tails-joint.html
Robert McGrath's Blog 