Colossal Biosciences says it used novel gene-editing technology to alter gray wolf DNA to breed the animals. Dire wolves recently featured prominently in the HBO series Game of Thrones.

Scientists working for Dallas-based biotech company Colossal Biosciences claim to have brought the dire wolf, which went extinct about 12,500 years ago, back to life.

OR-25, a male gray wolf formerly of eastern Oregon’s Imnaha Pack, lies in a meadow after being radio-collared by Oregon wildlife officials in 2014. Endangered gray wolves have gained more ground ...