What is "nimravinae"

The Nimravinae are a subfamily of the Nimravidae, an extinct family of feliform mammalian carnivores sometimes known as false saber-toothed cats. They were endemic to North America, Europe, and Asia from the Middle Eocene through the Late Miocene epochs ( Bartonian through Tortonian stages, 40.4—7.2 mya), spanning about . Centered in North America, the radiation of the Nimravinae from the Eocene to Oligocene was the first radiation of cat-like carnivorans.