The most famous rhino in the world has died, leaving behind two aging females and a hole in our world.

Sudan northern wrhite rhino

This is the face of extinction.

Sudan, the world’s last male northern white rhino (Ceratotherium simum cottoni), died Monday at Ol Pejeta Conservancy in Kenya. He was 45 years old and is survived by just two females, 27-year-old Najin and 17-year-old Fatu, neither of which are capable of breeding due to their own various health problems.

Perhaps the most famous rhino in the world, Sudan’s aging visage has graced magazine covers and newspaper articles around the world. In most of those photos he was seen accompanied by rifle-bearing guards that stood guard around the clock to protect him and his family from the threat of poachers, which continue to plague rhino populations wherever they still live.

Most recently the dating app Tinder called Sudan “the most eligible bachelor in the world,” a promotional effort that raised thousands of dollars for the conservation effort at Ol Pejeta.

“We on Ol Pejeta are all saddened by Sudan’s death,” Richard Vigne, Ol Pejeta’s CEO, said in a press release late Monday night. “He was a great ambassador for his species and will be remembered for the work he did to raise awareness globally of the plight facing not only rhinos, but also the many thousands of other species facing extinction as a result of unsustainable human activity. One day, his demise will hopefully be seen as a seminal moment for conservationists worldwide.”

The northern white rhino’s road to extinction was a long and painful one. The subspecies, which once roamed several nations in central Africa, were heavily poached throughout the first part of the 20th century, mostly to feed the rampant desire for their horns, which have been erroneously linked to traditional health treatments in China.

By 1997 the wild population of northern white rhinos had dropped to just 25 animals, all in Garamba National Park in the Democratic Republic of the Congo. Nine years later that population had fallen to just four lonely animals. Poachers, emboldened and enabled by war and conflict, probably got them, too. Repeated searches in 2007, 2008 and 2011 failed to find any evidence that they had survived.

That wasn’t quite the end, though. Eight aging, non-breeding northern white rhinos remained, all living in zoos: two at the San Diego Wild Animal Park and six at Dvůr Králové Zoo in the Czech Republic.

In 2009 four of the Dvůr Králové rhinos were flown to Ol Pejeta in Kenya, where it was hoped that the feel of their native sun on their backs and earth beneath their feet would inspire them to start breeding and save their species from extinction, possibly by mating and producing hybrid young with related southern white rhinos (C. s. simum).

The simple act of returning to Africa helped immensely. The animals were in “pretty poor state” when they first arrived, but “within six months of their being here their skin had improved, their toenails had improved, the whole condition of the animal had completely changed,” Richard Vigne told me in 2014. “They became semi-wild very quickly.”

And yes, there were some mating attempts, but no pregnancies ensued. Meanwhile, the last captive rhinos at San Diego and Dvůr Králové slowly passed away from old age, as did one of the four at Ol Pejeta, a male named Suni, who expired in 2014.

Now Sudan has joined the list of the dead. In all likelihood, Najin and Fatu will not be far behind.

That doesn’t mean Ol Pejeta or the worldwide conservation community have given up. For the past few years, scientists have collected sperm from the (now gone) male northern white rhinos and anticipate trying to extract eggs from the females at some point later this year. The hope is that someday that genetic material could be used to implant a fertile egg into a rhino of a different species, resulting in the (re)birth of a northern white.

That possibility of that plan working, like all such de-extinction attempts, still seems remote, but at least it still exists.

And so, for now, do the last two female northern white rhinos. Now they, like Sudan before them, are the faces of this species slowly fading away into extinction.

Previously in Extinction Countdown:

John R. Platt

is the editor of The Revelator. An award-winning environmental journalist, his work has appeared in Scientific American, Audubon, Motherboard, and numerous other magazines and publications. His “Extinction Countdown” column has run continuously since 2004 and has covered news and science related to more than 1,000 endangered species. He is a member of the Society of Environmental Journalists and the National Association of Science Writers. John lives on the outskirts of Portland, Ore., where he finds himself surrounded by animals and cartoonists.