Thousands of species of amphibians are endangered and hundreds have already disappeared, but in recent years, a team of scientists and conservationists have re-discovered some of these “lost” species and uncovered previously unknown varieties. Here: Miniature glass frog. (Photo by Robin Moore)

Clowns take part in the annual pilgrimage to the Basilica of Our Lady Guadalupe to pay homage to the Virgin of Guadalupe in Mexico City December 16, 2014. Dressed in colourful costumes, hundreds of clowns from all over Mexico walked towards the Basilica to give thanks to the virgin for the work they have received. (Photo by Carlos Jasso/Reuters)

Father Christmas arriving at the Arding and Hobbs store in Clapham Junction, London, 2nd November 1926. (Photo by H. F. Davis/Topical Press Agency/Getty Images)

A police poses on the durians during festival durian on the giant mount of durian at northern slopes of Mount Arjuna in East Java. Each year, nine villages in Wonosalam district hold a festival to give thanks for an abundance of this stinky, spiky fruit, which they pile in a 10-meter-high pyramid and distribute among the hungry masses. (Photo by Sigit Pamungkas/JG Photo)

A Palestinian social activist working for the International South South Cooperation (Cooperazione Internazionale Sud Sud, or CISS) entertain children who are patients inside a hospital in Gaza City August 31, 2015. Activists working for the Italian non-profit NGO use entertainment and humour to help bring treatment to children suffering from psychological trauma in the Gaza Strip. (Photo by Mohammed Salem/Reuters)

Barking mad owners have proved they really do look like their pets – by performing impressions of their own dogs. In a series of hilarious “paw”-traits, owners pull their best faces to look like their pooches. Snapped by photographer Ines Opifanti, people stuck their tongues out, yawned and tilted their heads in curiosity at the camera. Opifanti, from Hamburg, Germany, came up with the idea while interacting with her own dogs, two pug/French bulldog crossbreeds. Here: Amina and Zazou the dog. (Photo by Ines Opifanti/Caters News)

“The Mikoyan MiG-31 (NATO reporting name: Foxhound) is a supersonic interceptor aircraft developed to replace the MiG-25 “Foxbat”. The MiG-31 was designed by the Mikoyan design bureau based on the MiG-25”. – Wikipedia

Photos: The Mikoyan MiG-31 “Foxhound”. Russia, April 2012. (Photo by Alexandr Pak; Source: LiveJournal)