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)

Shaymaa Ismaa’eel, a 24-year-old Muslim woman passes by a group of angry protesters at an Islamic conference in Washington, DC on April 21, 2019. In response, she crouched in front of them and flashed a peace sign. The photo, posted on Instagram, prompted an outpouring of support. (Photo by Shaymaa Ismaa'eel/Instagram)

Manuelle aka the Snake Woman poses for photographs with a beer as she promotes the fnnual Beer Festival Oktoberfest in Cologne, Germany on September 22, 2014. (Photo by Federico Gambarini/EPA/EFE/Rex Features/Shutterstock)

A graffiti, portraying a woman, is seen in Medellin, Colombia on November 19, 2017. Mural graffitis from different artists, street art can be seen in almost every city on Earth, but street arts raw power and potential for change was felt by me most intensively in Medellins Comuna 13, previously one of Colombias most dangerous neighbourhoods, in fact Communa 13 was constant battleground between gangs, narcos, paramilitaries and the government, but today you would hardly recognise it. (Photo by Juancho Torres/Anadolu Agency/Getty Images)

A cat tries to find dry ground around an apartment complex in Houston after Hurricane Harvey hit on Aug. 30. Harvey made landfall in South Texas on August 25, leading to days of downpours that dumped more than 50 inches of rain. Harvey damaged or destroyed about 200,000 homes as the storm system flooded much of Houston and smaller coastal communities. (Photo by Scott Olson/Getty Images)

Visitors watch dinosaur models at Haitang Bay Rice Paddy Park on January 24, 2018 in Sanya, Hainan Province of China. The Haitang Bay Rice Paddy Park featuring 323 full-size dinosaur models was officially opened to the public on Thursday. (Photo by Yin Haiming/China News Service/VCG via Getty Images)

Artist German Vinogradov acts in the performance of the burning of installation, devoted to Maslenitsa, or Pancake Week, a pagan holiday marking the end of winter, in the village of Nikola-Lenivets, Kaluga region, Russia, February 17, 2018. (Photo by Maxim Shemetov/Reuters)

On the second straight day of record-setting temperatures, Maddy Hacker is hoisted up by friend Jasmine Harper, both of McLean, Virgnia, as they attempt an acrobatic stunt in front of the U.S. Capitol in Washington, U.S., February 21, 2018. (Photo by Kevin Lamarque/Reuters)