And in a few studies it was predominantly nocturnal behavior.

在一些研究中，它主要是夜间行为。

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。