Many lizard species have the ability to detach their own tails, a trick known as ‘self-amputation’. This is mostly done in self defence, enabling lizards to distract their predators and flee, leaving their tails behind. The process where many reptile species, such as lizards, can drop their appendages and regenerate them is known as caudal autotomy. The specifics of caudal autotomy have been puzzling scientists for many years, but now, a team in Abu Dhabi has figured out what stops lizards from losing their tails on a daily basis.
Lizard tails contain plug and socket-like prongs called fracture planes. These fracture planes are arranged in rows and can be detached at varying lengths depending on the predator. Dr. Song and his team at New York University discovered that these prongs contain mushroom-like pillar structures, containing small nanopores on the surface. These pillars are attached quite firmly to the tail and prevent it from detaching during regular movement, however, when the tail is bent they allow the tail to be released.
To test this theory, the tails of three lizards were carefully amputated and the structures of the fracture planes and nanopores on the micropillars were meticulously studied using an electron microscope. With further experiments, the research team confirmed that the pillars contain imprints and cracks which prevent tails from staying on or being completely removed. This means that lizards can begin to detach their tails when approaching oncoming danger, but also stop the process once it is safe. A discovery like this is vital to understanding the evolutionary aspects of lizards and how their tails are only detached when necessary.
