Reptiles
Pygmy Leaf Chameleon
Brookesia nana · also called pygmy leaf chameleon, nano-chameleon
The pygmy leaf chameleon is a chameleon small enough to sit on the end of your finger. Described only in 2021, from a single mountain in northern Madagascar, the adult male measures about 22 millimetres from nose to tail — which makes it a strong candidate for the smallest reptile on Earth.
Overview
The pygmy leaf chameleon is known from one patch of montane rainforest on the Sorata massif in far northern Madagascar. The male is about 13.5 mm snout to vent and 22 mm in total length; the female is larger, at around 29 mm total. It belongs to Brookesia, the group of tiny ground-dwelling leaf chameleons. It hunts mites and springtails in the leaf litter with a pinhead-sized tongue strike.
A leaf on the floor
By day it forages among fallen leaves; at night it climbs a short way up grass stems and low branches to sleep out of reach of ground predators. It does not shift colour like the big chameleons — it is a permanent leaf-brown, relying on simply looking like dead litter.
Outsized male anatomy
The tiny male has proportionally very large genitalia, close to a fifth of its body length, which researchers link to the need to mate with a much bigger female.
Status
The pygmy leaf chameleon is Critically Endangered. It is known from one degraded mountain forest, under pressure from clearance for farming, and a species confined to a single shrinking site meets that category almost regardless of how many individuals are alive now. Madagascar holds both this animal and, in Parson’s chameleon, one of the largest chameleons in the world.
Pygmy Leaf Chameleon: common questions
Is the pygmy leaf chameleon really the smallest reptile in the world?
It is the leading candidate. When it was described in 2021, the adult male, at about 13.5 millimetres from snout to vent and 22 millimetres in total length, was the smallest known of all the roughly 11,500 reptile species. A few other tiny reptiles come close, including other Brookesia leaf chameleons and some minute geckos from the Caribbean, so the title is held by a narrow margin and could change if smaller adults of a related species turn up. Only the female of this species is a little larger, which is normal for the group.
How can a chameleon be that small and still work?
All the standard chameleon equipment is present, just miniaturised — independently swivelling turret eyes, a projectile tongue, gripping feet with fused toes, and a prehensile-tending tail, all scaled to an animal that fits on a fingertip. It hunts prey that is itself tiny, mainly mites and springtails, so a pinhead-sized tongue strike is enough. Being this small does bring costs, such as a high rate of water loss and vulnerability to being eaten by things as ordinary as a large spider, which is one reason it sleeps up off the ground.
Why does the male have such large genitalia?
In this species the female is noticeably bigger than the male, and biologists who described it suggested that the male's proportionally very large hemipenes, the paired reproductive organs of male squamates, are an adaptation to that size difference, helping a small male mate successfully with a much larger partner. Extreme genital size relative to body size is seen in several small Brookesia chameleons and appears to track how mismatched the sexes are.
Why is it endangered if it was only just discovered?
Because everything about its known distribution points to high risk. Every specimen has come from one small area of montane forest on a single Madagascan mountain, and that forest is being cleared and degraded for agriculture like much of the island's remaining woodland. A species confined to one shrinking patch of habitat, with no known populations elsewhere, meets the criteria for Critically Endangered almost regardless of how many individuals are currently alive, because a single event such as a fire or continued clearance could remove its entire range.