Nature Uses Screws and Nuts: Previously Unknown Musculoskeletal System Discovered in WeevilsScienceDaily (July 5, 2011) — A musculoskeletal system so far unknown in the animal world was recently discovered in weevils. The hip of Trigonopterus oblongus does not consist of the usual hinges, but of joints based on a screw-and-nut system. This first biological screw thread is about half a millimeter in size and was studied in detail using synchrotron radiation. The discovery is reported by the current issue of the Science magazine.
screw and nut. This increases the mobility
of the leg. (Credit: KIT)
of components. "Now, we found that nature was first in inventing screws and nuts, because weevils have been using this construction for about 100 million years already," Alexander Riedel from the Karlsruhe State Museum of Natural History says. This museum supplied the weevil samples studied. The detailed three-dimensional images of the joints were made at the national ANKA synchrotron radiation source of Karlsruhe Institute of Technology.
As a rule, weevils are clumsier than many other beetles, e.g. cara-bidae. Transformation of a hinge joint into a screw joint, however, allowed them to move their legs further down, which made them better climbers. The Trigonopterus oblongus weevil analyzed here lives on twigs and foliage in the jungle of
"Meanwhile, we have also studied other weevil species and always found screw joints," explain Riedel and van de Kamp. "Obviously, this joint exists in all weevils, of which more than 50,000 species exist worldwide." In this case, the researchers would have identified the screw joint to be a so far unknown basic feature of the weevil family. The best known species in
The three-dimensional image reconstructions of the joint of Trig-onopterus oblongus of half a millimeter in size were made by means of the newly installed microtomograph of the ANKA synchrotron radiation source. "It extends the existing ensemble of synchrotron imaging techniques for wide application in life sciences," says Tilo Baumbach, Head of the ANKA synchrotron radiation source. "External users can now apply modern systems, from long-wave terahertz radiation to the highly brilliant X-radiation used in this case."
1. T. van de Kamp, P. Vagovic, T. Baumbach, A. Riedel. A Biological Screw in a Beetle's Leg. Science, 2011; 333 (6038): 52 DOI: 10.1126/science.1204245