Didiereaceae plant (Alluaudiopsis sp.), Spiny Forest, Hazofotsy, Southern Madagascar, Africa

A sea star shimp (Periclimenes soror), swims through a forest of spines on the back of a crown-of-thorns starfish, Micronesia, Pacific

Black Spiny-tailed Iguana (Ctenosaura similis), Chichen Itza, Yucatan, Mexico, North America

Didiereaceae plant (Alluaudia sp.), Spiny Forest, Hazofotsy, Southern Madagascar, Africa

Verreaux's Sifaka (Propithecus verreauxi) feeding on spiny Alluaudia sp., Spiny Forest, Berenty Reserve, Southern Madagascar, Africa

Didierea Forest, Spiny Forest, Hazofotsy, Southern Madagascar, Africa

Didierea Forest, Spiny Forest, Hazofotsy, Southern Madagascar, Africa

Baobab tree in Spiny Forest, Parc Mosa a Mangily, Ifaty, South West Madagascar, Africa

An adult black spiny-tailed iguana (Ctenosaura similis) basking in the sun, Caletas, Costa Rica, Central America

Baobab tree at night in a spiny forest reserve, Ifaty, Madagascar, Africa

An Echidna on the forest floor of the Macquarie Pass National Park, New South Wales, Australia, Pacific

An Echidna on the forest floor of the Macquarie Pass National Park, New South Wales, Australia, Pacific

Biosphere 2, self-sustaining ecosystem, cactus in front of facility with tropical rainforest, Oracle, Arizona, USA, North America