Update (April 22): The court has amended its order, removing the words “writ of habeas corpus.” Read more at Science .

Yesterday, a judge from New York’s Supreme Court granted two chimpanzees a writ of habeas corpus, effectively giving them a measure of legal standing that previously only applied to humans.

The writ came from the New York Supreme Court, which is hearing arguments in a lawsuit the Nonhuman Rights Project filed against Stony Brook University asking for the release of two chimpanzees involved in research into the evolutionary origins of bipedalism. The ruling compels representatives from Stony Brook to respond in court on May 6 to the Nonhuman Rights Project’s claim that two great apes, Hercules and Leo, are being “unlawfully detained.” Two other chimps, which are in private captivity, are involved in the lawsuit but weren’t named in the ruling.