Scientists may have just discovered the world’s smallest reptiles living on the rainforest floor in Madagascar. The tiny chameleons are so small that they fit on a human fingertip.
According to study co-author Frank Glaw, a reptile expert at the Bavarian State Collection of Zoology in Munich, the male and female specimens were spotted on a mountainside by a local guide during an expedition in 2012.
“You really have to get down on your knees to find them,” Glaw told AP News. “They are obviously camouflaged and they move very slowly.”
The international team of researchers from Germany and Madagascar named the species Brookesia nana, or nano-chameleon. The body of the male lizard is about 13.5 millimeters in length. This is at least 1.5 millimeters smaller than the previous record holder, another member of the Brookesia family.
Glaw explained that confirming Brookesia nana as the smallest reptile species will require finding more of them, which could take several years.
CT scans revealed that the female harbored two eggs, which confirmed that it was an adult. While the length of the male specimen was 22 millimeters from top to tail, the female is quite a bit larger, with a length of around 29 millimeters.
The size difference among the genders may explain why the male lizard was found to have genitals that were almost one-fifth of its body size. The researchers said that the “well-developed” genitals may allow the smaller male chameleon to mate with the larger female.
The scientists recommend for Brookesia nana to be listed as critically endangered for its protection. In Madagascar, chameleons are threatened by deforestation.
“The new chameleon is only known from a degraded montane rainforest in northern Madagascar and might be threatened by extinction,” wrote the study authors.
Dr. Mark Scherz was one of the experts involved in the discovery. In a blog post, he referred to Brookesia nana as “a spectacular case of extreme miniaturization.”
Dr. Scherz noted that the forests where the chameleons were found are still well connected with others across the north of the island. “So this tiny new chameleon violates the pattern of the smallest species being found on small islands. That suggests that something else is allowing/causing these chameleons to miniaturize.”
The study is published in the journal Scientific Reports.