The secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

Rocky the cat's recovery from a nerve condition in his legs is coming along swimmingly – thanks to regular hydrotherapy sessions at a 20ft-long swimming pool in United Kingdom in the second decade of March 2022. The two-year-old wears a life vest to help keep him afloat and needs a plastic toy to lure him from one end of the pool to the other. (Photo by Max Willcock/BNPS Press Agency)

A five meters high sculpture “Pentateuque” created by Contemporary French artist Fabien Merelle, is displayed in Central, business district of Hong Kong, Tuesday, May 21, 2013. The artwork brings to real life the fantastical and seemingly impossible act of an average man balancing a gigantic elephant. The elephant and the man are modeled on one at the Singapore Zoo and on the artist himself. (Photo by Kin Cheung/AP Photo)

A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, May 22, 2015. In Sudan, which faces insurgences in the western region of Darfur and along its border with breakaway South Sudan, as well as double-digit inflation and high unemployment, life goes on for young people in the capital Khartoum. (Photo by Mohamed Nureldin Abdallah/Reuters)

This Thursday, January 22, 2015 photo made with a long exposure shows the glow from a Noctiluca scintillans algal bloom along the seashore in Hong Kong. The luminescence, also called Sea Sparkle, is triggered by farm pollution that can be devastating to marine life and local fisheries, according to University of Georgia oceanographer Samantha Joye. Noctiluca itself does not produce neurotoxins like other similar organisms do. But its role as both prey and predator tends can eventually magnify the accumulation of toxins in the food chain, according to R. Eugene Turner at Louisiana State University. (Photo by Kin Cheung/AP Photo)

These chilling images prove there is no sign of life at this abandoned tuberculosis treatment hospital. Johnny Joo, 24, captured the eerie shots of the desolate TB ward, in Perrysburg, New York. Where equipment lies gathering rust and walls are left crumbling. The photojournalist, from Cleveland, Ohio, stumbled upon the facility, which shut its doors in 1995, before shooting what remains of the historic site. Johnny said the facility, named after Buffalo Mayor James Nobel Adam, remains something of an unknown quantity as it is surrounded by more than 500 acres of forest land. (Photo by Johnny Joo/Caters News)

Charlotte fights a monster with a “wand” in her bedroom in Laure Fauvel's “Terreurs”, 2014, in Paris, France. An imaginative photographer has brought to life monsters that haunt children's nightmares. Armed with sticks, wands and swords the eight and nine year-olds appear to be getting the upper-hand against the villains. Parisian photographer Laure Fauvel, 22, said: I wanted the children not be victims and to fight the monsters. (Photo by Laure Fauvel/Barcroft Media)

A 10-year-old pet goldfish named George undergoes veterinarian Tristan Rich's scalpel to remove a life-threatening head tumor in this handout picture taken September 11, 2014 and provided to Reuters by the Lort Smith Animal Hospital in Melbourne, Australia. In a 45-minute long procedure described by Rich as “fiddly”, the fish was sedated by water laced with anaesthetic, the tumour removed and the wound sealed with tissue glue followed by antibiotics and painkillers. (Photo by Reuters/Lort Smith Animal Hospital)