The researchers found that nocturnal behavior evolved as long as 300 million years ago, in carnivores like Sphenacodon ferox and herbivores like Tritylodon longaevus.

研究人员发现，早在 3 亿年前，食肉动物如 Spenacodon ferox 和食草动物如 Tritylodon longaevus 就已经进化出夜间行为。