She passed a self-awareness test that almost no animal can. Then courts decided that wasn't enough to make her a person. She died at 55.

Happy, a Bronx Zoo elephant who gave researchers new insight into the animal's behavior and became the crux of a closely watched animal rights case, has been euthanized at age 55.

A Bronx Zoo elephant who gave researchers new insights and became the crux of a closely watched animal rights case has died.