Hidden beneath the leaf litter of a northern Malagasy forest lives a chameleon so slight that it could tumble off the tip of your finger. Measuring just under 30 millimeters from snout to tail, the newly described species, Brookesia nana, may be the smallest reptile on Earth, researchers report January 28 in Scientific Reports.
The male holotype of Brookesia nana sp. nov. has a snout–vent length of 13.5 mm (total length 21.6 mm) and has large, apparently fully developed hemipenes, making it apparently the smallest mature male amniote ever recorded. The female paratype measures 19.2 mm snout–vent length (total length 28.9 mm) and a micro-CT scan revealed developing eggs in the body cavity, likewise indicating sexual maturity. The new chameleon is only known from a degraded montane rainforest in northern Madagascar and might be threatened by extinction.
Most miniaturized Brookesia are rainforest species, which inhabit mostly forests in lowlands (e.g. B. minima on Nosy Be) and rarely at higher elevations > 1000 m a.s.l. (e.g. B. tedi on Marojejy). Other species prefer dry forest, especially on karstic underground5,12. The majority of species exhibit very small ranges, with only few species being known from more than two locations. This microendemism may be related to the complex topography in northern Madagascar where these and other Brookesia species are predominantly distributed. Their diminutive size combined with their small ranges have contributed to the fact that much of the diversity of this clade has been overlooked until recently.
Source: F. Glaw et al. . Scientific Reports. Vol. 11, January 28, 2021. doi: 10.1038/s41598-020-80955-1.