Alex Mustard / Backlit detail of branching fire coral (Millepora alcicornis) showing the hair like polyps, filled with stinging nematocysts. East End, Grand Cayman, Cayman Islands. Caribbean Sea.

Robin Chittenden / Peregrine falcon (Falco peregrinus) on statue's head, Norwich Cathedral, Norfolk, UK, June

Daniel HEUCLIN / Malayan Tiger (Panthera tigris jacksoni) in river, Malaysia. Captive in natural setting.

Alex Mustard / A portrait of an Atlantic stargazer (Uranoscopus scaber) buried in the sand waiting to ambush prey. This species can also use its hairy tongue as a lure. El Cabron, Gran Canaria, Canary Islands, Spain...

Juergen Freund / CT scan of injured Green turtle 'Angie' (Chelonia mydas) from the Cairns Turtle Rehabilitation Centre, Cairns Diagnostic Imaging. Queensland, Australia

Juergen Freund / CT scan of injured Green turtle 'Angie' (Chelonia mydas) from the Cairns Turtle Rehabilitation Centre, Cairns Diagnostic Imaging. Queensland, Australia

Gavin Hellier / Ancient carved stone heads of the gods, the god Antiochus, Nemrut Dagi (Nemrut Dag), on the summit of Mount Nemrut, UNESCO World Heritage Site, Cappadocia, Anatolia, Turkey, 2008

Gavin Hellier / Giant monolithic stone Maoi statues at Rano Raraku, Easter Island, Rapa Nui, Chile, South America 2008

Konrad Wothe / Stone engravings of Giraffes in Wadi Mathendous, Wadi Barjuj, Stony Desert, Libya, Sahara, North Africa, November 2007

Bernard Castelein / Village life, woman covering her face, in doorway to village home, with peacock art on walls, Sawai Modhopu, Rajasthan, India

Petra Wegner / Mixed Breed puppy, 12 weeks / Pug crossbred, sitting on small sofa with reindeer toy.

Klaus Echle / Stockdove (Columba oenas) shadow on the trunk of beech tree. Black Forest, Germany, April.

Brent Stephenson / The fallen Moai at Ahu Hanga Tetenga with the coastline in the background. Hanga Tetenga, Easter Island, October 2009.

Juergen Freund / Ancient pictographs (rock / cave paintings) of fish and sea creatures on karst limestone formations. Sunmalelen area, Raja Ampat, West Papua, Indonesia, January 2010

Oriol Alamany / Moai face at the restored archaeological site of Ahu Ko Te Riku in Tahai Ceremonial Center in Hanga Roa, Easter Island (Pascua or Rapa Nui), Unesco World Heritage Site, November 2004

Oriol Alamany / Rock paintings of Terns (Sterna sp) at Ana Kai Tangata cave, Easter Island (Pascua or Rapa Nui), Pacific Island, Unesco World Heritage Site, November 2004

Edwin Giesbers / Fanged pitcher plant (Nepenthes bicalcarata) on white background, Sarawak, Borneo, Malaysia

Oriol Alamany / Petroglyph of an Elephant at Khaz'ali Canyon, Wadi Rum Protected Area, Jordan, April 2009

Oriol Alamany / Moai stone statue at dusk on the slopes of the quarry at Rano Raraku volcano, Easter Island Pacific ocean, November 2004

Oriol Alamany / Silhouette of Moai statue at dawn in Ahu Ko Te Riku, restored archaeological site of Ahu Tahai, Hanga Roa, Easter Island, Pacific ocean, November 2004

Doug Allan / Close up of two stone sculptures / Moai at Ahu Ahivi/Ahu Akivi , Easter Island, South PacificMoai October 2009

Patricio Robles Gil / Ancient cave paintings of people, deer and wild sheep, Sierra de San Francisco, Baja California, Mexico

Angelo Gandolfi / Prehistoric rock painting of a fox (Vulpes vulpes), Albxerri cave, Pais Vasco, Spain. July 2008.

Angelo Gandolfi / Prehistoric rock painting of Reindeer in Tito Bustillo cave, Asturias, Spain. July 2008.

Roy Mangersnes / Svalbard reindeer (Rangifer tarandus platyrhynchus) grazing, Adventsdalen, West coast of Spitsbergen, Svalbard, Norway, March

Nick Upton / Cherhill white horse, first cut into chalk downland in 1780, Wiltshire, UK, spring 2009

Rob Tilley / Rock engravings of the native american Pueblo people, Chaco Culture National Historical Park, New Mexico, USA, February 2009

Elio Della Ferrera / Southern plains grey / Hanuman langur {Semnopithecus dussumieri} sitting on arm of statue of Buddha. Sri Lanka

Enrique Lopez-Tapia / Aboriginal rock art depicting people and animal, possibly a crocodile. Kakadu National Park, Northern Territory, Australia.

Enrique Lopez-Tapia / Aboriginal rock art depicting people and animal, possibly a crocodile. Kakadu National Park, Northern Territory, Australia.

Jeff Foott / Pictographs depicting people with arms in air and animal, possibly a Coyote. Dating from 10,000 years ago. El Palmarito cave paintings, Sierra de San Francisco, El Vizcaino Biosphere Reserve, Baja Cal...

Jeff Foott / Pictographs depicting people with arms in air and animal, possibly a Coyote. Dating from 10,000 years ago. El Palmarito cave paintings, Sierra de San Francisco, El Vizcaino Biosphere Reserve, Baja Cal...

Claudio Contreras / Prehistoric rock art with depiction of Pronghorn antelope. Boca de San Julio cave, San Francisco Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico.

Claudio Contreras / Prehistoric rock painting at La Pintada cave, Pronghorn antelope, Bighorn sheep and people depicted, San Francisco Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico.

Claudio Contreras / Prehistoric rock painting of Pronghorn antelope and people, at La Pintada cave. San Francisco Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico.

Claudio Contreras / Prehistoric rock painting of Pronghorn antelope and people. La Pintada cave. San Francisco Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico.

Claudio Contreras / Prehistoric rock painting of Pronghorn antelope and Turkey vulture. La Pintada cave. San Francisco Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico, March

Claudio Contreras / Guide in front of prehistoric rock paintings of Bighron sheep and people. La Pintada cave, San Francisco Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico.

Claudio Contreras / Prehistoric rock painting of Pronghorn antelope, Mule deer and people. El Palmarito cave, Santa Martha Sierra, El Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico.

Ernie Janes / RF- Swallow (Hirundo rustica) adult and Chaffinch (Fringilla coelebs) perched on Weather Vane England, UK, May. (This image may be licensed either as rights managed or royalty free.)

Pal Hermansen / Artists erecting sculptural artwork 'The other side'. Ostfold County, Norway. July 2014. Model released.

Pal Hermansen / Artwork 'Unsatiable' by artist Astri Tonoian. Valer, Ostfold County, Norway. July 2014.

Inaki Relanzon / Animal petroglyphs between 5,000-15,000 years old years ago, Khavtsgait Petroglyph Mountain, Gobi desert, Govi Gurvan Saikhan National Park, South Mongolia. June 2015.

Steve O. Taylor (GHF) / Rock paintings of Rhinoceros, Tsodilo hills UNESCO World Heritage Site, Botswana.

Steve O. Taylor (GHF) / San rock paintings of antelopes, Matobo Hills, Zimbabwe. January 2011.

Pete Oxford / Petroglyph by San Bushman of Elephant. Private game ranch, Great Karoo, South Africa.

Stephen Dalton / Close-up of a birch seed (Betula sp) floating on pond, UK.

Enrique Lopez-Tapia / Wood totem. Efate Island, Shefa Province, Vanuatu, September 2008.