Rex Features
A gorilla who shot to fame for her extraordinary mastery of sign language has died.
Koko, who featured on the cover of National Geographic twice, passed away in her sleep at the age of 46, the Gorilla Foundation announced on Wednesday.
"Koko touched the lives of millions as an ambassador for all gorillas and an icon for interspecies communication and empathy. She was beloved and will be deeply missed," the foundation said.
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