Researchers discovered what may be the smallest reptile on the planet in the rainforests of northern Madagascar, reports Jason Bittel for National Geographic. The new miniscule lizard is a species of chameleon named Brookesia nana, and is so small its entire body can fit on a fingertip, according to a new paper published last week in the journal Scientific Reports.
A lizard called the Caribbean gecko (Sphaerodactylus ariasae) is the former record holder for smallest reptile on Earth, but the changing of the guard is made somewhat murky by the fact that only the male B. nana specimen found by scientists is smaller than the Caribbean gecko. The minute male B. nana measures just half an inch from nose to the base of the tail, reports Brandon Specktor for Live Science. The female, on the other hand, comes in at three-quarters of an inch in length. According to National Geographic, the former title holder for the smallest chameleon is a member of B. nana’s own genus, Brookesia micra.
“It feels a little silly to be like, ‘Oh, it’s a few millimeters smaller than this other thing,’” Mark Scherz, an evolutionary biologist at the University of Potsdam and study co-author, tells National Geographic. “But when millimeters are two or three percent of your body size, then that’s a lot of change. Most of science happens in these small, incremental steps.”
The paper also notes that besides the miniscule total length of the male, he distinguished himself by possessing unusually large genitals for his size—almost 20 percent of his body length. Researchers hypothesize that males of the species may sport their oversized sex organs, a two-pronged affair called hemipenes in lizards and snakes, to more effectively copulate with the significantly larger B. nana females. And, if you’re wondering why these researchers were so concerned with this tiny lizard’s undercarriage, it’s because the shape of reptile genitals are often species specific. So, it was one of the first things they examined while sussing out whether they had found a new species, Sherz explained in a series of tweets about the research.
In general, reptile hemipenes (paired ~penises) can often be species-specific in their morphology, meaning that you can use them to identify species. The same is true of beetles and many other arthropods. In the case of chameleons, the structures can be… absolutely crazy (14/21) pic.twitter.com/0cIIzGjRm7— Dr Mark D. Scherz (@MarkScherz) January 28, 2021
So far only two members of the new species have been recorded by scientists, so it is possible their kind’s true average length is longer or shorter than the measurements reported in the study. Other members of the Brookesia genus are tiny as well, and despite being chameleons they don’t have much capacity for color changing, Scherz tells Isaac Shultz of Gizmodo.
By virtue of residing in the rainforests of Madagascar, which are being cut down to make room for agriculture and livestock, B. nana is almost certainly threatened with extinction despite a lack of knowledge of its true conservation status, according to Live Science.
Fortunately, B. nana’s habitat in an area known as the Sorata massif was recently enshrined in a new protected area, but the reality in Madagascar is that many of its people have little economic recourse but to cut into its remaining forests to grow crops or raise animals, Scherz tells National Geographic.
“It’s all good and well to say, ‘Oh, I really hope that people stop deforesting this forest,’” says Scherz. “But until the economic future of Madagascar changes, there’s no hope for any of its wildlife because the people have to eat.”