The Nano chameleon, or Brookesia nana, is a tiny chameleon found in the mountainous rain forest of North Madagascar, in an area called the Sorata massif. They are only about the size of a sunflower seed and can sit on a fingertip. The Nano chameleon may be the smallest reptile on the planet. Because their so tiny, their prey consists of mites and springtails, which they hunt using their projectile tongue. They hunt by day over leaf litter, retreating to the safety of the grass at night. Whenever they see the blades part for a predator, this chameleon will simply disappear into the underbrush.
So far only two individuals have been found on a research trip in 2012: a male and a female. The male’s overall body length is 22 millimeters and the female’s is 29mm, showing signs of sexual dimorphism. The small known population makes it difficult to figure out if these two individuals are just small, or if the species itself is the smallest reptile. Without prior knowledge, it previously wasn’t known if these chameleons were even adults. After close observation and a Micro CT scan, it was found that the female was carrying eggs and the male was sexually mature, so the researchers concluded that the nano chameleons were adults. The researching team does not know why the Nano chameleon is so small. The Brookesia micra chameleon is another tiny chameleon that is only millimeters bigger than the Nano.
Image courtesy of Frank Glaw
The discovery of such a small chameleon raises the question: how small can a vertebrate be? Since smaller animals have a larger ratio of surface area to volume, they are prone to water loss. At some point, there is also a limit to how small a vertebrate can be while containing everything it needs to survive. Small creatures often have smaller skulls and overlapping bones. Because of these factors, at some point, there has to be a limit for how small a vertebrate can be.
Bittel, J. (2021, February 10). This tiny chameleon may be world's smallest reptile. Retrieved April 22, 2021, from https://www.nationalgeographic.com/animals/article/tiny-chameleon-smallest-reptile-discovered-madagascar
Staff, S. (2021, February 01). Meet the nano-chameleon, a new contender for the title of world's smallest reptile.Retrieved April 22, 2021, from https://phys.org/news/2021-02-nano-chameleon-contender-title-world-smallest.html
Reuters. (2021, February 04). This newly discovered chameleon is so tiny it can fit on your fingertip. Retrieved April 22, 2021, from https://www.nbcnews.com/science/science-news/newly-discovered-chameleon-tiny-can-fit-fingertip-rcna246
Cover Image courtesy of Frank Glaw.