Carol Walker / Claro and Cremesso, two third year male cremello Wild horse / mustang colts that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, on their new ranch in Colorado, US...

Carol Walker / Trainer Rich Scott with Cremosso, a young male cremello Wild horse / mustang that had been rounded up from a McCullough Peak herd and put up for adoption, trainer teaching it to be led in paddock, Jul...

Wild Wonders of Europe / Radisics / Ice forming stalagmite structures in Ledena Pecina (an ice cave) inside Obla Glava (Rounded head peak) Durmitor NP, Montenegro, October 2008

Wild Wonders of Europe / Radisics / Ice formation in Ledena Pecina (an ice cave) inside Obla Glava (Rounded head peak) Durmitor NP, Montenegro, October 2008

Wild Wonders of Europe / Radisic / Ice forming stalagmite structures in Ledena Pecina (an ice cave) inside Obla Glava (Rounded head peak) Durmitor NP, Montenegro, October 2008

Claudio Contreras / Rounded earthstar mushroom (Geastrum saccatum), Lacandon Rainforest, Montes Azules Biosphere Reserve, southern Mexico, August

Claudio Contreras / Rounded earthstar mushroom (Geastrum saccatum), Lacandon Rainforest, Montes Azules Biosphere Reserve, southern Mexico, August

Ashley Cooper / Windswept tree at Brimham Rocks, Nidderdale, Yorkshire, England, UK, October 2009.

Francisco Marquez / Mares and foals rounded up into corral. During the annual round up of mares and foals. Donana National Park, Spain.. September 2014.

Georgette Douwma / Orbicular burrfish or Shortspine porcupinefish (Cyclichthys orbicularis) with a Bluestreak cleaner wrasse ( Labroides dimidiatus) Ambon, Indonesia.

Franco Banfi / Rounded bubblegum / Bubble coral (Plerogyra sinuosa) with two Gobies (Gobiidae) on it, Lazi Pier, Dumaguete, East Negros Island, Central Visayas, Philippines, Pacific Ocean.

Bryan and Cherry Alexander / Rounded mounds of vegetation by the disused ANARE, Australian National Antarctic Research Expedition, huts at Atlas Cove. Heard Island, Heard and McDonald Islands UNESCO World Natural Heritage Site Su...

Constantinos Petrinos / Acoel flatworms (Waminoa sp.) on Bubble Coral (Plerogyra sinuosa) Lembeh Strait, North Sulawesi, Indonesia.

Linda Pitkin / Banggai Cardinalfish (Pterapogon kauderni), sheltering against Bubble Coral (Plerogyra sinuosa) Lembeh Strait, North Sulawesi, Indonesia, February 2016

John Cancalosi / Hertfordshire Puddingstone, a conglomerate of well rounded flint pebbles, embedded in a matrix of fine pale coloured sand, all bound together by hard natural silica cement, Hertfordshire, england

Martin Gabriel / Rounded boulder with crack, Erebuni State Reserve near Yerevan, Armenia

Georgette Douwma / Acoel flatworms (Waminoa sp) on polyps of Bubble coral (Plerogyra sinuosa) Indonesia. This flatworm can cover the whole surface of some corals, leaving them no way to catch plankton and their symbioti...

Georgette Douwma / Acoel flatworms (Waminoa sp) on polyps of Bubble coral (Plerogyra sinuosa) Indonesia. This flatworm can cover the whole surface of some corals, leaving them no way to catch plankton and their symbioti...

Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Alex Hyde / Cave Pearls, formed as dripping water rich in calcium salts deposits calcite around a small nucleus (often a sand grain). The constant movement of each cave pearl by the dripping water keeps them roun...

Pete Oxford / Domestic Cattle (Bos taurus) herd being rounded up, Saddle Mountain, Rurununi, Guyana

Pete Oxford / Domestic Cattle (Bos taurus) herd being rounded up, Saddle Mountain, Rurununi, Guyana

John Cancalosi / Rapakivi granite, a hornblende biotite granite containing large rounded crystals of orthoclase mantled with oligoclase, Finland.

Mike Read / New Forest ponies being rounded up, Wiers near Brockenhurst, New Forest National Park, Hampshire, England, UK, September.

John Cancalosi / Spherulite in the Silver Cliffs, Colorado. In petrology, spherulites are small, rounded bodies that commonly occur in vitreous igneous rocks.

Carol Walker / Claro, Cremosso and Mica, three wild horses / mustangs rounded up from the McCullough Peak herd and Adobe Town Herd in Wyoming, adopted by photographer Carol Walker. Running in their corral, Colorado,...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Attending the Wild Horse Festival in Santa Fe, New Mexico, meetin...

Carol Walker / Wild horses / mustangs. Mica (right), rounded up from Adobe Town Herd Management Area in Wyoming and Claro (left), rounded up from McCullough Peak herd. Both adopted by photographer Carol Walker. Colo...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Running in his corral, Colorado, USA.

Carol Walker / Photographer Carol Walker with her adopted wild horses / mustangs Claro, Cremosso and Mica, rounded up from the McCullough Peak herd and Adobe Town Herd in Wyoming. Resting in their corral, Colorado,...

Carol Walker / Photographer Carol Walker with her adopted wild horses / mustangs Claro, Cremosso and Mica, rounded up from the McCullough Peak herd and Adobe Town Herd in Wyoming. Resting in their corral, Colorado,...

Carol Walker / Photographer Carol Walker with her adopted wild horses / mustangs Claro, Cremosso and Mica, rounded up from the McCullough Peak herd and Adobe Town Herd in Wyoming. Resting in their corral, Colorado,...

Carol Walker / Wild horses / mustangs. Mica (right), rounded up from Adobe Town Herd Management Area in Wyoming and Cremosso (left), rounded up from McCullough Peak herd. Both adopted by photographer Carol Walker. M...

Carol Walker / Wild horse / mustang called Cremosso, rounded up from McCullough Peak herd in Wyoming and adopted by photographer Carol Walker. Trotting in his corral, Colorado, USA.

Carol Walker / Wild horses / mustangs. Mica (left), rounded up from Adobe Town Herd Management Area in Wyoming and Claro (right), rounded up from McCullough Peak herd. Both adopted by photographer Carol Walker. Meet...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Touching noses with a mare belonging to trainer Rich Scott. Color...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Being led out of his trailer by trainer Rich Scott, arriving at C...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Saddled and preparing to be ridden for the first time by trainer...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Saddled and being ridden for the first time by mounted trainer Ri...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. With trainer Rich Scott, saddled and preparing to be ridden for t...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. With trainer Rich Scott, saddled and preparing to be ridden for t...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. With trainer Rich Scott, saddled and preparing to be ridden for t...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. With trainer Rich Scott, saddled and preparing to be ridden for t...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Saddled and preparing to be ridden for the first time, Colorado,...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Preparing to be saddled and ridden for the first time, Colorado,...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker (pictured). Attending a trial obstacle clinic, designed to increas...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker (pictured). Attending a trial obstacle clinic, designed to increas...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Wearing a saddle for the first time, with trainer Rich Scott. Col...

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Walking in pasture, Colorado, USA.

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Wearing a saddle for the first time, Colorado, USA.

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker. Running in pasture, Colorado, USA.

Carol Walker / Wild horse / mustang called Claro, rounded up from McCullough Peak herd in Wyoming and adopted by photographer Carol Walker (pictured). Colorado, USA.

Carol Walker / Wild horse / mustang called Claro, rounded up from McCullough Peak herd in Wyoming and adopted by photographer Carol Walker (pictured). Colorado, USA.

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker (pictured). Colorado, USA.

Carol Walker / Wild horse / mustang called Mica, rounded up from Adobe Town Herd Management Area in Wyoming and adopted by photographer Carol Walker (pictured). Colorado, USA.

Philippe Clement / Rounded nodules on the beach near Osmington Mills, made of calcite-cemented sandstone from the Bencliff Grit Formation along the World Heritage Site Jurassic Coast, Dorset, UK, November 2012

Philippe Clement / Rounded nodules on the beach near Osmington Mills, made of calcite-cemented sandstone from the Bencliff Grit Formation along the World Heritage Site Jurassic Coast, Dorset, UK, November 2012

Brent Stephenson / Hector's dolphins (Cephalorhynchus hectori) breaking the surface showing the distinctive patterning and rounded dorsal fins. Akaroa Harbour, Canterbury, New Zealand.

Brent Stephenson / Hector's dolphin (Cephalorhynchus hectori) breaking the surface as it breathes showing the distinctive patterning and rounded dorsal fin. Akaroa Harbour, Canterbury, New Zealand.

Carol Walker / Long horned cattle rounded up by cowboys, Wyoming, USA, February 2012, model released

Carol Walker / Wild horses / Mustangs rounded up in corral, Great Divide Basin, Wyoming, USA, October 2011

Carol Walker / Carol Walker with her male cremello Wild horse / mustang colt Claro that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, Colorado, USA, August 2011, model released

Carol Walker / Two third year male cremello Wild horse / mustang colts Cremello and Claro that had been rounded up from a McCullough Peak herd, Wyoming, and put up for adoption, waiting to be transported to new home...

Carol Walker / Claro and Cremesso, third year male cremello Wild horse / mustang colts that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, on their new ranch in Colorado , USA,...

Carol Walker / Third year male cremello Wild horse / mustang colt Cremesso that had been rounded up from a McCullough Peak herd, Wyoming, and put up for adoption, at new home in Colorado, USA, July 2010

Carol Walker / Claro and Cremesso, two third year male cremello Wild horse / mustang colts that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, on their new ranch in Colorado, US...

Carol Walker / Close up of eye of male cremello Wild horse / mustang colt, Cremesso, that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, Colorado, USA, December 2011

Carol Walker / Close up of eye of male cremello Wild horse / mustang colt, Cremesso, that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, Colorado, USA, August 2011

Carol Walker / Carol Walker training her second year male palomino Wild horse / mustang colt, Mica, that had been rounded up from the Adobe Town herd, Wyoming, and put up for adoption, Colorado, USA, March 2011, mo...

Carol Walker / Carol Walker training her second year male palomino Wild horse / mustang colt, Mica, that had been rounded up from the Adobe Town herd, Wyoming, and put up for adoption, Colorado, USA, March 2011, mo...

Carol Walker / Carol Walker training her second year male palomino Wild horse / mustang colt, Mica, that had been rounded up from the Adobe Town herd, Wyoming, and put up for adoption, Colorado, USA, March 2011, mo...

Carol Walker / Carol Walker training her second year male palomino Wild horse / mustang colt, Mica, that had been rounded up from the Adobe Town herd, Wyoming, and put up for adoption, Colorado, USA, March 2011, mod...

Carol Walker / Male second year palomino Wild horse / mustang colt, Mica, that had been rounded up from the Adobe Town herd, Wyoming, and put up for adoption, Colorado, USA, January 2011

Carol Walker / Male palomino second year Wild horse / mustang colt, Mica, that had been rounded up from the Adobe Town herd, Wyoming, and put up for adoption, Colorado, USA, May 2011

Carol Walker / Carol Walker with her male cremello Wild horse / mustang colt Claro that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, Colorado, USA, August 2011, model released

Bryan and Cherry Alexander / Herd of Reindeer / caribou (Rangifer tarandus) being rounded up at their winter pastures on the Chukotskiy Peninsula. Chukotka, Siberia, Russia, 2010

Bryan and Cherry Alexander / Blue iceberg rounded by sea water, Antarctica, 2009.

Carol Walker / Two young male cremello Wild horses / mustangs Claro and Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, waiting to be transported to new home, April 2010

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, in stable with trainer Rich Scott, Colorado, USA, February 2011, model released

Carol Walker / Young male cremello Wild horse / mustang Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, mounted trainer Rich Scott teaching it to be led in paddock, August 2010...

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, in stable with trainer Rich Scott, Colorado, USA, February 2011, model released

Carol Walker / Young male cremello Wild horse / mustang Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, trainer Rich Scott training horse to accept colours, Colorado, USA, July...

Carol Walker / Two young male cremello Wild horses / mustangs Claro and Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, in yard, May 2010

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, being led into trailer by trainer Rich Scott, Colorado, USA, February 2011, mod...

Carol Walker / Young male cremello Wild horse / mustang Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, trainer Rich Scott teaching it to be led in paddock, August 2010, model...

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, in pen with trainer Rich Scott, Colorado, USA, February 2011, model released

Carol Walker / Two young male cremello Wild horses / mustangs Claro and Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, in yard, June 2010

Carol Walker / Young male cremello Wild horse / mustang Claro that had been rounded up from a McCullough Peak herd and put up for adoption, with trainer Rich Scott, learning to be handled, July 2010, model released

Carol Walker / Two young male cremello Wild horses / mustangs Claro and Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, in yard, May 2010

Carol Walker / Two young male cremello Wild horses / mustangs Claro and Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, with trainer Rich Scott, learning to be handled, July 20...

Carol Walker / Young male cremello Wild horse / mustang Cremosso that had been rounded up from a McCullough Peak herd and put up for adoption, trainer Rich Scottteaching horse to lift front leg, Colorado, USA, July...

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, in pen with trainer Rich Scott, Colorado, USA, January 2011, model released

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, in pen with trainer Rich Scott, Colorado, USA, January 2011, model released

Carol Walker / Grey Mustang / Wild horse colt foal Mica, rounded up from the Adobe Town herd, Wyoming, and adopted by the photographer, in pen with trainer Rich Scott, Colorado, USA, January 2011, model released