Pyxis
One of the smallest, rarest, and most fascinating groups of tortoises in the world
These tortoises are masters of survival in an unforgiving landscape, perfectly adapted to the dry, spiny forests and sandy plains of Madagascar’s southwest. Though tiny in size, they embody some of the most remarkable evolutionary strategies ever seen in reptiles, combining exquisite beauty with delicate ecological balance. Sadly, both species are now Critically Endangered, making the genus Pyxis a symbol of both the island’s natural wonder and its environmental fragility.
Despite their small size, they are among the most strikingly patterned reptiles on Earth. The Spider Tortoise (P. arachnoides), for example, bears a dark, glossy carapace adorned with radiating yellow lines that resemble a spider’s web—hence its name. The Flat-shelled Tortoise (P. planicauda), in contrast, has a flatter shell with more muted tones, allowing it to hide among fallen leaves and sandy soils. Both species share several unique physical traits, such as a hinged plastron (underside of the shell) that allows them to close themselves tightly when threatened—a rare feature among tortoises that provides excellent protection from predators and desiccation.
The genus Pyxis is perfectly adapted to Madagascar’s spiny desert ecosystem, a region characterized by long dry seasons, sparse vegetation, and brief, intense rains. During the short rainy season, these tortoises emerge from dormancy to feed, mate, and lay eggs. They graze on succulent plants, grasses, wildflowers, fallen fruits, and cactus pads, obtaining most of their water from food. When the environment dries out again, they retreat underground or beneath leaf litter, entering a state of aestivation—a deep, summer-like sleep that can last up to eight or nine months. During this time, their metabolism slows dramatically, allowing them to survive without food or water until the rains return. It’s a remarkable adaptation to one of the most challenging climates on the planet.
Species in this genus
Flat-backed spider tortoise
Unlike most tortoises, it spends more than half the year inactive, waiting patiently for the rains
Spider tortoise
Can go up to eight months without food or water, surviving entirely through aestivation