Suzi Eszterhas / Red-shanked douc langur (Pygathrix nemaeus) infant sucking thumb while caretaker holds it. Animal was rescued from illegal wildlife trade, Endangered Primate Rescue Center, Cuc Phuong National Park, V...

Ingo Arndt / Close up of foot of Chimpanzee {Pan troglodytes} note opposable toe

Ingo Arndt / Orang utan hand holding branch close-up {Pongo pygmaeus abelii} Sumatra, Indonesia

Andy Rouse / Mountain gorilla (Gorilla beringei) baby held by mother, Rwanda

Floris van Breugel / A hot spring in the West Thumb Geyser Basin, Yellowstone National Park, Wyoming. The colors are a result of thermophilic bacteria living in the hot springs. December 2010.

Paul D Stewart / Restoration of the Iguanodon by Alice B. Woodward from Lydekker's The Royal Natural History' Frederick Warne and co, 1896. This is one of the first reconstructions to correctly show the Iguanodon's th...

Andy Rouse / Mountain gorilla (Gorilla beringei beringei) close up of feet showing toe curled around branch, Volcanoes NP, Virunga mountains, Rwanda

Jeff Vanuga / Blue Funnel Spring, West Thumb Geyser Basin, Yellowstone Nationa Park, Wyoming, USA

Nigel Cattlin / Redshank (Persicaria maculosa) growing as arable weed. England, UK. September.

Nigel Cattlin / Redshank (Persicaria maculosa) growing as arable weed. England, UK. September.

Nigel Cattlin / Redshank (Persicaria maculosa), an annual arable weed. Berkshire, England, UK. August.

MYN / Joao P. Burini / Maldonada redbelly toad on hand (Melanophryniscus moreirae) on human thumb, Atlantic forest, Itatiaia National Park, Brazil. Meetyourneighbours.net project.