A team of international scientists has uncovered a new tiny but well-endowed chameleon which may be the world's smallest reptile species, according to a study published in the journal Scientific Reports on Thursday.
The miniature male was discovered during a German-Madagascan expedition in the north of Madagascar and measured only 13.5 millimetres, according to the Bavarian State Collection of Zoology in Munich.
This makes Brookesia nana, as it was called, the smallest male among almost 11,500 known reptile species, said Frank Glaw of the Bavarian collection, who co-authored the article.
At the same time, the miniature chameleon's penis measured 18.5% of his body size, the scientists said.
Glaw said that small chameleon species tend to have the largest penises, so-called hemipenes, in proportion to their body size, based on a comparison of 51 chameleon species.
One explanation for this could be the difference in size among the sexes, as females tend to be larger than males among small chameleons, the researchers said.
The team also found a female Brookesia nana which measured 19 millimetres.
"Therefore the extremely miniaturized males would need relatively bigger genitals for successful mating with their significantly larger females," said co-author Miguel Vences of the Technical University in Braunschweig.
The scientists were unable to discover more than two specimens of the miniature chameleon. Small chameleon species often have a very small habitat that can span only a few square kilometres.