A chimpanzee whose ability to learn American Sign Language suggested but did not prove that the animal could engage in humanlike conversation died on Tuesday, The New York Times reported today.

The chimp, named Washoe for the Nevada county in which she grew up, was taught well over 100 signs by two cognitive scientists, R. Allen Gardner and Beatrix T. Gardner, in the 1960s, and it was initially thought that she was actually communicating with human language.

Later research, however, suggested that in making signs Washoe was only aping her human teachers. But that finding was not conclusive either, and the debate has continued.

Washoe later retired to the Chimpanzee and Human Communication Institute at Central Washington University. She died in bed at the age of 42, “surrounded by staff members and other primates who had been close to her,” the Times reported. Her death came just two months after that of Alex, an African gray parrot also renowned for his cognitive achievements. —Andrew Mytelka