Feb 02, 2021 15:20:00

Discovered the world's smallest new chameleon, male genital size accounts for the largest proportion of the body

On January 28, 2021, reptile scholar

Frank Rein and his colleagues at the Bavarian State Museum of Zoology published a research paper in the open access journal Scientific Reports that they 'discovered a new species of chameleon on Madagascar.'

Extreme miniaturization of a new amniote vertebrate and insights into the evolution of genital size in chameleons | Scientific Reports
https://www.nature.com/articles/s41598-020-80955-1

World's smallest reptile fits on your fingertip | Live Science
https://www.livescience.com/worlds-smallest-male-reptile-large-genitals.html

The species, named 'Brookesia nana,' is the smallest of all known reptiles, with a mature male individual measuring only 13.5 mm from the nose to the cloaca , according to a study by Rein et al. That is. Although the female individual found in the same survey was found to be 19.2 mm larger than the male, it is said that only these two individuals were found despite the hard research of Mr. Rein and others.

When Rein et al. Conducted a micro CT scan to investigate the sexual maturity of males, the male genitals have a shape called the hemipenis found in chameleons and snakes, and the size is large. It was found that 2.5 mm occupies about 18.5% of the total length.

This is the fifth largest of the 51 other species of Brookesia micra found on Madagascar, and according to Rain et al., 'The smaller the chameleon, the larger the genitals tend to be.' The individual with the largest genitals is

Brookesia tuberculata , which is said to occupy about 33% of the total length.

Regarding this tendency, Miguel Vance of the Technical University of Braunschweig, who co-authored the paper, attributed this tendency to ' sexual dimorphism ' in which individual traits differ depending on gender. It required a large genital organ to mate. '

Below is a female Brookesia nana.