Saturday, February 27, 2010
Toe Pads & Tails
The adhesive toepads of lizards are one of life's most spectacular inventions. Humans are even using this innovation as the inspiration for new adhesive nanostructures. Did you know that some geckos have similar adhesive structure on the tips of their prehensile tails, as well as on their toes? I caught one such gecko in northern Australia a number of years ago during an expedition to Arnhem Land with Jane Melville and Museum Victoria. The species we found - Pseudothecadactylus lindneri - is closely related to geckos on New Caledonia and could be found wandering Arnhem Land's impressive rock outcrops at night. The photo above is of a juvenile P. lindneri and close-ups of the toepads (top) and tailtip (bottom) of an adult animal. It seems likely that the tailpad results from similar genetic and developmental mechanisms to the toepads found in the same animal, but this has yet to be investigated in any detail. Remarkably similar toepads are known to have evolved independently in geckos, anoles, and skinks.