The Madagascar chameleon Brookesia nana is identified as the smallest reptile in the world when it is only about 13.5mm long, can fit on the tips of human fingers.
Brookesia nana is an extremely small species of chameleon found in the rainforests of northern Madagascar. Researchers recently described a male and female of this species in a study published in the journal Scientific Reports.
They were amazed at the male’s unusually small size. Measuring just 13.5mm, the adult male is the smallest adult reptile ever described. In fact, the male B. nana was even smaller than his female, with a muzzle-body length of 19.2 mm.
“Since the general outline of the reptile’s body is quite similar to that of mammals and humans, it is fascinating to see how these miniature creatures and their organs can be,” says Frank Glaw. .
However, not all of Brookesia nana’s organs were so reduced. Male lizards have a pair of reproductive organs called hemipenes – two inverted tubular genitalia inside the male body, until it’s time to mate.
The hemipenes of B. nana are 2.5 mm long at full maturity, equivalent to 18.5% of its total length.
Surprisingly, this is not an unusual trait among the world’s smallest lizards. The team found that the genital length of the chameleon involved ranged from 6.3% to 32.9% of the male’s total body length, with an average of 13.1% across 52 species.
“This reveals an interesting pattern which is that the smaller species generally have the larger proportionately large genitals,” said study co-author Mark Scherz of the University of Potsdam in Germany.
According to Scherz, this could be linked to the size difference between the males and females of these tiny reptiles.
However, since there are only two known specimens of Brookesia nana, scientists still do not know how endangered the creatures are. But as Madagascar’s rainforest faces a significant threat from invasive human activities such as deforestation and agriculture, these lizards may also be at risk.
