KEY POINTS

  • Researchers discovered a "nano-chameleon" that's so small it can fit on a fingertip
  • While it may possibly be the world's smallest reptile, its male species have relatively larger genitals
  • The species may be endangered already because of their degraded habitat

Researchers may have just found the smallest reptile in the world. The newly discovered 'nano-chameleon' from Madagascar is so small it can fit on the tip of a finger.

In a recent study published in the journal Scientific Reports, an international team of researchers reported discovering a tiny new chameleon species from a rainforest in northern Madagascar. This particular chameleon, now officially named the Brookesia nana or B.nana, is unique because it is reportedly as small as a sunflower seed.

The only known male of the species has a total body length of just 22 millimeters. This makes it the smallest known male among "higher vertebrates," study first author Frank Glaw said, as noted at the Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB) news release. On the other hand, the female is bigger in size with a total length of 29 millimeters. Researchers also found, using a micro-CT scan, that the female specimen had two eggs.

"Based on two individuals, we describe a new, extremely miniaturized chameleon, which may be the world's smallest reptile species," the researchers wrote.

Its close competitor could be its relative, the Brookesia micra chameleon species, which in 2012 was photographed on top of the head of a match, National Geographic noted.

Nano-Chameleon, Big Hemipenis

Apart from possibly being a contender to the world's smallest reptile title, the researchers also found something rather interesting about the nano-chameleon's male specimen. Its genital is larger relative to its body! When they compared its genital to that of 51 other chameleon species, they found that it is actually the fifth-largest. 

Researchers explained that the male specimens could have larger genitals because the females are bigger.

"As a result, the extremely miniaturized males of the small species need relatively larger genitals in order to successfully mate with the larger females," study co-author Miguel Vences said in the SNSB news release.

Extreme Miniaturization

Such an "extreme miniaturization" has been observed before, the researchers said. But why this particular species is so small is still unknown.

In the "island rule," for instance, small mainland mammals grow large in islands while large mainland mammals grow smaller. But with lizards, small species get even smaller in islands, while the larger ones get bigger.

However, the case may not apply to the B. nana because its habitat is in Madagascar's Sorata massif mountains, not on an island.

New But Already Endangered

For now, only two specimens of the nano-chameleon have been observed. Still, there are concerns that they may already be threatened from extinction because of their habitat degradation.

In fact, the researchers noted that based on the currently available knowledge on the species, they could be classified as "Critically Endangered" under the IUCN Red List.

"Unfortunately, the habitat of the Nano-Chameleon is under heavy pressure from deforestation, but the area has recently been designated as a protected area, and hopefully that will enable this tiny new chameleon to survive," study co-author Oliver Hawlitschek of the Centrum für Naturkunde in Hamburg said in the news release.

Chameleon Pictured: Representational image of a chameleon. Photo: Pixabay